Showing posts with label WiMAX. Show all posts
Showing posts with label WiMAX. Show all posts

Tuesday 18 August 2009

Indian subscribers getting taste of Mobile Broadband

Lots of interesting developments are happening in India at the moment. The first and the most basic being MNP or Mobile Number Portability finally becoming a reality. For the first time users will be able to move operators and retain their number. This will change the way the users will use their phones. For example most users use their mobiles as secondary phones for making calls while they give their landline numbers to important people. The reason being they are not sure how long they will stick with the current operator. If they change the operator they will get a new number. I think that this will definitely change with MNP.

MNP is not the only thing. Many operators and equipment manufacturers are waiting for the 3G spectrum auction for some time now. The auction was recently postponed for variety of reasons. The auction will let the private operators to bid for the spectrum and they can decide if they want 3G or WiMAX or LTE. The state run MTNL and BSNL have already launched 3G and in Northern India but there have been not many takers yet. Maybe the people are but sceptical right now or maybe the lack of devices. The other thing is that people are maybe not sure if the technology they invest in will be around tomorrow or not.

MTNL is keen to experiment with WiMAX but it does not want to do it alone. There are many companies in India that have developed WiMAX protocol stacks so it may be a boost for these generally small and medium sized companies if WiMAX is deployed by MTNL. The only problem with WiMAX is that there are hardly big global names with any WiMAX devices/equipment. As a reult the prices could be higher and the consumers may have less choice. 3G and LTE will help in this scenario. Qualcomm for example is already looking forward to getting a big chunck of the Indian market.

India has a very big pool of keen technologists and they will whole heartidly embrace mobile broadband and the variety of apps/mobiles but only when they know that there will be stability and reliability. Once the ball starts rolling then the snowball will turn into an avalanche. The question is not if, but when.

Tuesday 7 July 2009

Smart Grids: New Wireless Revolution

In the past two years, M2M (machine-to-machine) applications have become one of the most talked-about topics in the wireless industry. While M2M apps can be used for many purposes (such as smart homes, smart metering/electricity meter reading, fleet management, mobile workforce, automobile insurance and vending machines) and in many sectors (such as healthcare, agriculture, commercial, industrial, retail and utility), smart metering applications--also known as smart grids--present the biggest growth potential in the M2M market today. With many leading wireless service providers and utility companies jumping on the bandwagon and the growing support from states like Texas and California, M2M applications are set to become very successful in the coming years.

AT&T in March announced a new alternative for electric utility companies looking to provide the benefits of smart grid technology to the residential sector. AT&T and SmartSynch are for the first time providing utilities with a cost-effective solution by combining a new suite of service plans from AT&T designed specifically for machine to machine (M2M) communications with SmartSynch's smart grid solutions already deployed at more than 100 utilities throughout North America.

With this new solution from AT&T and SmartSynch, electric utility companies will now be able to concentrate on efficient electricity delivery rather than being distracted by building, maintaining, expanding and upgrading a communications network. This new solution offers a cost-effective point-to-point configuration model in which each meter communicates directly with the utility over the AT&T wireless network.

Smart grids combine "smart meters", wireless technology, sensors and software so customers and utilities can closely monitor energy use and cut back when the availability of electricity is stretched to its limit. The IP-based smart grid model ultimately helps consumers understand the economics of their consumption patterns so they can make intelligent decisions about their power consumption. The smart grid technology will also help to enhance reliability and energy efficiency, lower power-line losses and provide utilities with the ability to remotely automate service, providing cost-savings for consumers.

Key benefits of the point to point smart meter solution to utility companies include:
  • improved speed of deployment over traditional meshed networks
  • the simplicity of an open standard, IP-based network
  • the ability to communicate directly with each meter.

How can T-Mobile, the fourth-largest cell phone carrier in the U.S., generate business in the face of dropping net additional subscribers and competition from low-cost cell phone companies? Get into the smart grid. Like AT&T and Verizon, T-Mobile is hoping to leverage its already built-out wireless networks to tap into the coming smart grid boom spurred by the stimulus package. On Thursday, T-Mobile plans to announce that it’s developing a durable SIM card that can be embedded in smart meters (as well as used for other industrial processes), and a new partnership with smart meter technology maker Echelon.

Mobile’s national director of Machine-to-Machine services, John Horn, told us that T-Mobile has been playing in the connected electric meter space for several years, including working with smart meter maker SmartSynch (AT&T has a deal with them, too), and he says the carrier has several utility pilot projects under way in the Pacific, Southwest and Midatlantic regions with an aggregate of “tens of millions” of smart meters. In some of those trials T-Mobile has been testing out its new smart meter SIM card, which is like the SIM card in your regular cell phone, but smaller — 5 by 6 millimeters — more durable and made of silicon, not plastic. Horn says the SIM, which can be connected to any of T-Mobile’s wireless networks, including 3G, can withstand the heat and environmental conditions of being outdoors in a smart meter much better than a standard SIM card.

One of the first smart meter makers to embed the new SIM is Echelon, which is also working with T-Mobile on a smart meter service that will run over T-Mobile’s wireless networks and, according to the companies, is significantly cheaper for utility customers. T-Mobile is just the latest phone company to drop its prices to attract utilities. AT&T and SmartSynch announced a similar deal last week. Horn said of T-Mobile’s smart grid price move: “We’ve broken historical pricing models.”

Network technologies including LTE, mobile WiMAX, WiFi and ZigBee potentially could be used for future smart grid applications. While it is still too soon to tell which technology is likely to become the big winner in this market, mobile WiMAX appears to have an edge over LTE due to mobile WiMAX's time-to-market advantage. Mobile WiMAX also has the advantage of being more reliable and secure than "pure" unlicensed technologies like WiFi. WiMAX can also count on support from leading companies like GE, Intel, Sprint Nextel, Clearwire, Motorola, Samsung and Google, among others.

Most importantly, WiMAX will enable carriers, utility companies and other key players to build open-standards based smart meters. Ultimately, through WiMAX, third parties will be able to develop many applications and devices, helping to reduce cost. With WiMAX chipsets currently running about $36, some observers believe that the cost could become as low as $8 or $6 in the next 18 months.

In the meantime, WiMAX-based smart meters are already available in the U.S. For instance, GE, in association with Intel and Grid Net software, has built one of the first WiMAX-based smart meters. Intel Capital and GE both invested in Grid Net in 2006. Companies competing with GE include companies like Trilliant, Itron, Silver Spring Networks (also one of GE's partners) and Landis & Gyr.

However, over time, LTE could become a valuable option for many companies involved in this space as LTE becomes widely adopted and prices associated with it start to come down. LTE's larger coverage capacity and ability to support a higher number of points should play a key role here. In our opinion, it will also become critical for LTE carriers to offer a decent revenue share with utility companies and other key players.

Although being a short-range technology, ZigBee could also have a role to play in the M2M apps space as several companies have expressed some interest in the technology. In fact, U.S.-based startup Tendril Networks is well positioned to become a pioneer in this space; the company, which teamed up with Itron and Landis & Gyr, has already developed a product called Tendril Residential Energy Ecosystem (TREE), compatible with various ZigBee-based devices to be used for smart grid apps inside homes.

Lastly, if fully secured, WiFi could also become a disruptor. WiFi-based smart grid apps appear to be gaining traction in the U.S. and Europe. For instance, the city of San Jose, in association with Echelon, is currently testing a whole smart streetlight network using WiFi-based smart grids set to be launched this summer. The system may receive federal stimulus money, and if it does the city plans to revamp the entire 65,000-light network, which would help reduce energy costs by 40 percent. That figure is consistent with the performance of two European cities: Milton Keynes in the United Kingdom and Olso in Norway, which have been implemented by Echelon.

From Ajit Jaokar's Open Gardens Blog:

While Telcos have historically rebelled against 'opening up', the US administration's emphasis on Open is creating huge opportunities for Telecoms and the Cloud

Broadband stimulus grants are tied to net neutrality rules, which means networks have to allow users to connect any device to the network

But this also leads to a huge opportunity because now Telecoms can extend their reach into the Smart Grid through MTM (machine to machine) applications which will generate a much higher number of network connections. These may have less ARPU (i.e. average revenue per user) but a greater number of actual connections with no need to subsidise devices. Hence, they could be profitable.

A smart grid starts with a 'smart meter' which is capable of two way communications and lets the user and provider manage electricity consumption in a more granular way. If the customer's power consumption can be captured in a granular manner, the provider can offer specials/ discounts to the customer. The added potential of smart grids arises from knowing data trends and also extend power management to other devices. These synergies fit well into LTE and home gateways and this explains with LTE and also explains Verizon's emphasis on Ipv6
The Verizon Itron partnership is an example of such a service and this service will be a part of Verizon's LTE deployment in the 700 MHz band for M2M apps.

The Zigbe alliance is also gaining traction as a result of this move by building wireless intelligence and capabilities into everyday devices and all this will lead to the 50 billion devices mark which suddenly does not sound so far away

On the services side, initiatives like Microsoft Hohm are being deployed and even if a utility isn't a part of Hohm, users can enter data directly which means that they can get more benefits the more they contribute to it.Google power meter is a similar initiative from Google.

The wider potential of this trend is discussed in an excellent article from Andrew GesmerEnergy Conservation From Zero to Sixty

Thus, Smart grids, LTE and the Cloud are a huge opportunity for the industry - but the privacy concerns with sensor networks and the Cloud will play an important part here.

Companies are building out the smart grid with various broadband technologies — cellular, WiFi, WiMAX — so why not good ol’ DSL? Smart grid sensor and software maker Current is touting a new smart grid partnership with DSL provider Qwest.

Current largely provides the sensors that monitor different conditions on the electrical network, like voltage and current, as well as the software that processes the sensor information for the utility customer. While Current is mostly focused on the distribution portion of the grid, it can also provide communication gear and sensors for smart meters and in-home gateways, which it is doing for Colorado utility Xcel Energy for its SmartGridCity rollout. Because Current needs to get its information back to the utility, it works with a number of companies that provide that network connection. The latest is Qwest, which Current started partnering with, and is currently working with, for Xcel Energy’s SmartGridCity plan (Qwest provides phone and broadband service in Colorado). The buildout of SmartGridCity is supposed to be completed soon, followed by an assessment of the network’s benefits.

What are the benefits of using DSL? Current’s senior vice president of business solutions, Mae Squier-Dow, says that because DSL is already widely available, using it speeds up the ability to deploy smart grid technology. And because the networks have already been built, she says, the option is more affordable for a utility than building out its own communications network. (Other companies argue that in the long run it’s cheaper to build and own the network). Since DSL is a proven technology, it can help smart grid projects gain access to stimulus funds meant for “shovel-ready” projects, Squier-Dow says.

DSL is also high-speed, so if utilities want to use the networks for more bandwidth-intensive services, they can. And DSL is based on Internet Protocol, so it can more easily connect with other IP-based networks and systems, which are ubiquitous. Ultimately DSL is a standard that’s been used for years, so utilities can be rest assured that the technology is highly reliable.

Tuesday 19 May 2009

LTE World Summit - Day 1 roundup

Before we start, I should mention that there have been no discussions showing LTE is better than WiMAX, etc. It is now assumed that WiMAX is no longer a threat and a competitor. There is also missing a discussion on Femtocells. I suppose that some Femto related discussions are planned for day 3.

I am going to cover the discussions in detail in the coming days (months) but here are some interesting tidbits.

It started with a presentation from Marc Fossier, France Telecom. An interesting fact about France he mentioned is that 40% of voice traffic is VoIP. They are present in 30 countries (generally by the name Orange) and they have 128 million customers. LTE rollout is planned for post 2011. They will be deploying WiMAX in some markets like Romania and some African countries. The main reason being that there is no 3G network there. Another key point of his presentation was that Mobile TV should be independent of the technology being considered and TDD works fine for that. Also SON (Self Organising Networks) will be very important feature that is needed when LTE is rolled out.

Klaus-Jurgen Krath from T-Mobile Germany gave T-Mobile statistics of 148 million customers and revenue of 9.2 Billion Euros. One of the things he mentioned is that at 2.6GHz, the cell radius is 0.3Km but if we move to 800MHz then the cell radius is around 3Km. Personally I am not sure if the frequency is something we should worry too much about. WiBro in Korea is I think using 2.3GHz and is working fine. Another thing mentioned is that the Backhaul is generally quite bandwidth limited so that needs to be improved. The operators should use Microwave or Fiber to overcome this backhaul problem. LTE Migration will also take time and initially it would be the third layer on top of GSM and 3G/HSPA but by 2020 it should be dominant technology. Right now Voice and SMS problem has to be solved asap. Personally I think SMS is not much of a problem and SMS can work on CS as well as PS. Operators can use SMS over PS for the moment. Femtocell according to Klaus is very important for LTE but Femtos will be successful only if they are Plug and Play for both operator and the consumer. His final point was that we should not dissapoint the customer by showing the peak rates, rather we should focus on average rate.

Ulf Ewaldsson from Ericsson mentioned that 80% of broadband subscribers by 2014 will be mobile. Another thing he said is that for LTE, it is possible to deliver 1GB for < 1 euro. (Capex only). Ericsson vision is that by 2020 there will be 50 Billion mobile broadband connections. Ericsson will be ready with LTE soon and by the year end peak rate of 42Mbps will be possible.

Alex Sinclair from GSMA talked on expanding the LTE ecosystem. There were lots of interesting facts and figures that I will have to mention seperately. There was also an intersting mention of the GRX (GPRS Roaming Exchange) that will need a completely new discussion.

In the Panel Discussion, Marc mentioned that Orange is not considering Femtocells for Residential market because of many unsolved technical problems like Price, Security, Spectrum Management, etc. On the business side they may have Femto, Pico or Micro depending on the need. Ed Candy from '3' mentioned that operators should focus on Macro rather than Femto because lots of spare capacity available. He mentioned that there is a business problem because somebody has to subsidise Femto, also too many Femtos can cause RF blackspots and operational dynamics are yet to be worked out.

Elio Florina from Telecom Italia (TiM) talked about LTE and HSPA deployment in Brasil. The main point being that initially they want to have complete 3G/HSPA coverage and then in future think about LTE.

Alan Hadden from GSA mentioned about GSA activities. I was surprised to hear that only 55,000 people view their website annually. This is because a simple blog like mine regularly gets between 20,000 and 25,000 views per month. Again there were lots of stats that I will write about later. Interesting point from his discussion was about the Digital Dividend band that can be used by LTE to increase the coverage.

Dave Marutiak, Microsoft spoke about Bearer Aware Applications. Dean has blogged in detail about this.

Ed Candy from '3' in his presentation highlighted an important point about the user experience. He said that for any service, user experience should be memorable so even after 2-3 years if the user has to use the same application than he should remember how it works. I think that there are hardly any services like this except those that are intutive to use. In Dec. 08, '3' saw people using 34million skype minutes and 68 million Facebook page views. It should be remembered that Facebook phone was launched in Dec itself. His message was that '3' will not be moving to LTE anytime soon because the current network is delivering whatever is required.

Roberto Di Pietro from Qualcomm spoke about the challenges faced by the chipset manufacturers. The main challenges is due to the fact that there are millions of combinations of different bands that the UE may need to support which is not practical and possible. They are focussing mainly on 2.6GHz at the moment and when the Digital Dividend band is available then they will implement chipset in that band as well.

Jorgen Lantto from ST-Ericsson and Sami Jokinen from Nokia gave their views on chipsets and handsets implementation respectively. According to Nokia, LTE handsets will be available by 2010. Initial deployments will be in FDD but later in TDD-FDD both.

Liesbet Van der Perre from IMEC discussed about the SDR implementation for LTE devices. Her presentation was more of updates on the previous IMEC info I have covered here.

Finally, I managed to squeeze myself into an Agilent workshop called 'LTE at the movies'. There were two parts to that 'MIMO MIA' and 'Honey who shrunk my mega bits'. The workshop lated 2.5 hours and I got a free Agilent LTE book. Lots of technical details that I will post seperately.

Please feel free to comment or correct me if I made any mistakes. You can also read Dean Bubley's take on the first day here.

I shouldnt finish without thanking the organisers who have done a good job in organising the event and for such wonderful hospitality (and food :).

Wednesday 4 March 2009

More mobile broadband ... with WiMAX this time

An interactive, online map by the WiMAX Forum and Informa Telecoms & Media’s World Cellular Information Service (WCIS) offers information on the many WiMAX deployments across the globe. Click here to access the map.

With investments already made into WiMAX, the wireless broadband technology will be able to withstand the current economic downturn in a year that will see some additional network deployments, according to the WiMAX Forum.

Because of the current economic climate, WiMAX providers are not being as aggressive with network deployments, but the forum estimates at least 100 more operators will launch commercial services this year.

The Forum says WiMAX now covers 430 million people or POPS, globally and are on a path to nearly double to 800 million people by end of 2010 and explode to 18 million by 2012. In-Stat forecasts LTE will have 23 million subscribers by 2013, but nearly 82 million mobile PCs with WiMax will ship in 2013.

So far, Mobile WiMAX is being offered in just two cities, Baltimore and Portland, Ore. On March 5th, Clearwire will announce which cities will be added next in the United States. Another nine cities are expected to roll out this year.

According to research firm In-Stat, WiMAX will continue to outpace LTE over the next few years and the technologies will take different paths. Verizon Wireless is expected to launch LTE commercially sometime next year but most operators will wait until 2011 or 2012.

Meanwhile, the WiMAX forum says there will be 100 certified products on the market this year, growing to 1,000 by 2011. The forum also expects growth to continue in Asia, Europe, Latin America and Africa.

Friday 28 November 2008

Femtocells as the starting point - more info

Informa has recently come up with a report titled "Opportunities for femtocells in the mobile broadband ecosystem: the economic case for LTE and 3G+". I found the following very relevant to this topic that I have blogged earlier about:

One idea is to use LTE initially as an access point rather than a full standalone network, which would bypass all the difficulties and delays that may happen in developing the core network for this technology. Here femtocells, picocells or GAN dual mode solutions could help operators to achieve this goal. As well as the time to market advantage, operators will also have a good opportunity to test LTE access networks and their business case for it before engaging in any wide scale network rollouts. This will obviously help them to minimize risks while giving them enough time to get their networks more stable and ready for the challenge.

Deploying LTE through femtocells is now an industry accepted solution as mobile operators can incrementally add capacity to their networks where it is most needed. This is expected to be in the home environment where 60% of communication is expected to take place during 2013. Instead of performing ‘forklift’ upgrades for their macrocell networks, mobile operators can test the LTE business case by initially launching LTE femtocell networks. Overall capex is expected to be much less than for a macrocell network – but on the other hand, LTE femtocells will only create localized coverage and capacity hotspots for a limited group of end users.

Several chipset and hardware platform manufacturers have launched products for LTE femtocells, including Picochip and Agilent. The upcoming 3GPP femtocell standard is expected to provide compatibility for LTE femtocells and mobile operators are expected to announce their LTE strategies in 2009. Informa Telecoms & Media expects that the majority of mobile operators – especially those that have invested heavily in 3G – will incorporate femtocells in their LTE strategies either for business case validation or for selective, incremental capacity upgrades for their mobile networks.

Wednesday 26 November 2008

Femtocells as the starting point

I blogged earlier about 'LTE Femtocell Layer as starting point'. During my visit to the LTE world summit, I didnt find (m)any takers for the idea initially. Then in his presentation, Prof. Simon Saunders, Chairman of Femto Forum, seemed to encourage the idea. As FemtoForum is technology neutral, he started with the case for WiMAX Femtocells. He quoted a VP from Comcast saying that Femtocells are "absolutely key to WiMAX" and he envisioned future services and packages that would encourage customers to use their WiMAX femtocells and stay on Comcast’s network.

Then he threw the following slide to the operators saying that introducing LTE network via Femtocell could be a way to roll out the LTE network.

In Release 8, HSPA based Femtocells will be standardised and Release 9 (De. 2009) will deliver LTE standards-based femtocells. Some operators are in hurry to roll out their LTE networks next year, since LTE home eNodeB's wont be standardised in time for them, maybe we will see LTE Femtocells as intial offering by some operators by mid-2010.

Sunday 23 November 2008

Delay in LTE can be blessing in disguise

Most of us know by now that Sprint and Clearwire is going to combine shortly to create a company which will trade into WiMax feverishly. The idea is that the joint company which will be called as Clearwire would foster competition in the mobile broadband arena and accelerate build out or deployment of advanced technologies such as WiMax. These are the kind of developments that keep LTE camp nervous but at the same time provide them some motivation as well.

With the merger it is anticipated that company's WiMAX network, to reach 140 million potential customers by 2010. It not a coincidence that Sprint chose WiMax as a 4G standard as it is available now and our customers want 4G now.

The company Clearwire says that it has deployed WiMAX in Baltimore and plans to deploy it in Chicago, Dallas, Philadelphia and Washington, D.C., pending the close of the deal. This development together with some other factors gives enough confidence to WiMax supporters that the technology would minimize the market penetration of LTE simply because WiMAX is coming to market first.

Everybody will agree with me that WiMax is definitely in a very good position and it is WiMax’s battle to loose as far as battle of 4G is concerned.

On that other hand I am learning that network operators are just now beginning to see a return on their 3G networks. This gives the operators some encouragement to say they won't be ready to upgrade to an OFDM-based technology until about the time LTE is ready and why should they if they are able to generate handsome revenues with the existing 3G technologies.
On the other hand this delay in deployment of OFDMA based technologies by operators does gives mobile WiMAX time-to-market advantage over LTE by at least two years.

The fact that LTE won't be ready for another two to three years may actually turn out to be a boon for LTE as the time frame will allow mobile operators to get as much life as possible out of their existing 3G networks. Incremental upgrades to enhanced 3G technologies such as HSPA+ and EV-DO Rev B will allow for almost the same data rates as the initial LTE deployments, which will effectively set the stage for large-scale LTE commercial rollouts in three to four years.
LTE has a further advantage because the majority of cellular operators around the world will choose LTE as their migration path given the fact that 3GPP has tabbed LTE as the next-generation standard for the GSM community.
It is certainly a truth that WiMAX is a very robust technology that has been quite successful in many parts of the world as a fixed broadband solution and will continue to do so, especially in under-served markets. Although mobile WiMAX networks are already going live thanks to Sprint/Clearwire and Korea Telecom, the prospect of additional mobile WiMAX networks from Tier 1 operators is looking pretty grim.

Lets see how hard the WiMax camp will fight and how shrewdly the LTE camp will play the game.

Saturday 22 November 2008

iBurst may give WiMAX run for money

One of the themes that emerged from the LTE World Summit was that no one was looking at WiMAX as a competitor for LTE. LTE is being thought as 'Mobile Broadband' whereas WiMAX is being thought more of as 'Low-mobility/Fixed Broadband'. They would serve different needs and their market will hardly overlap. I have blogged about iBurst in the past and I think it may give some competition to WiMAX.

David Brunnen from Personal Broadband UK (cant find their website) gave an interesting perspective on iBurst and even though many people have not heard of it, it can still compete in the market. They have a big presence in Australia and last year won the spectrum for the whole of Ireland + Northern Ireland between 1785 - 1805MHz. Even though they have won the 20MHz band, they think that they can do with 5MHz or maximum of 10 MHz. They have also partnered with iBand and would probably allow roaming between them.

The main thing about iBurst is that it has very good spectral effeciency and an average throughput of around 600kbps. Data Rate of 1.061Mbps downlink/ 346Kbps uplink with System capacity 24.4Mbps downlink/ 7.9 Mbps uplink is supported. At the same time it offers high mobility with handovers at speed of over 100kmph. The cell radius is 1.5-3km in urban and 5-7km in rural area. Because of adaptive antennas, the same frequency can be reused and the interference can be reduced thereby increasing the cell capacity.

The biggest problem with iBurst is that there are very few players. Kyocera is the only base station supplier. On the devices side, Kyocera is the lead player but there are other new players like Dovado which has won some big contract with first US iBurst operator and Moovera (bought by Icomera) which also has some similar devices.

Last year Kyocera announed that iBurst has more than 140,000 subscribers. This year iBurst South Africa has been shortlisted for an award of "Best Operator in Developing Country". In last 6 months they have increased the subscriber numbers by 30%.

With the big players heavily invested in HSPA+/LTE and many others having a foot in WiMAX, it would be interesting to see how a possible iBurst success might be viewed. I would like to hear from people who have experienced this technology on what their feeling is about iBurst.

For more information on the iBurst technology, see Kyocera's iBurst Technology homepage.

Latest news on iBurst available from website.

Sunday 2 November 2008

Will there be a winner in LTE and WiMax debate?

In the past there have been so many developments within WiMax and LTE in terms of where the two technology stands. Which technology is on the rise or which will eventually be a 4G technology is a never ending discussion.

On a regular basis I do get to know that either the LTE or WiMax camp claiming victory over another.

In a recent WiMAX World conference in Chicago, some advocates were quick to claim a WiMAX victory in the 4G technology race. The mantra or refrain for most of the sessions was that WiMAX is here and it's paving the way for 4G.

In the past few months there has been significant development in WiMax camp coordinated with the launch of WiMax services. In September Sprint-Nextel's launched the commercial mobile WiMAX service (called Xohm) in Baltimore. This definitely helped the buzz for WiMax to reach a new high. But as always together with the excitement, lies some anxious moments as everybody is now watching Xohm's debut to see how it fares with consumers.

There is no doubt that plenty of stake is riding on Sprint's Xohm launch. Clearwire also has got its own anxious moments with this launch as it was in last May that Clearwire announced it would merge with Sprint Nextel's WiMAX business to create a new company, also called Clearwire. The deal, which is expected to close by year-end, includes a $3.2 billion investment from Google, Intel, Comcast, Time Warner and others.

Although the above scenario really present a competitive and rosy picture for WiMax but even one of mobile WiMAX's biggest fans, admits that it's unlikely that WiMAX (or any one technology for e.g. LTE) will win the 4G debate.

In my view and so as I believe most of the people expects that the wireless industry will always have at least two technologies, perhaps more. My view can be supported with the idea of most of the operators going for HSPA+ technology. With operators eager to generate more revenue with the ever increased data rate requirements together with the delay in LTE there is no choice but to go for HSPA+. Which in my view has always been the best way to move forward as I am always a big fan of HSPA+ till LTE arrives?

This means that there may be some operators that will evolve along the HSPA+ path and never opt to deploy 4G or a 4G-like technology.

If the situation were to develop like I mentioned above then I don't think it is going to be as black and white as one (technology) wins and one loses. A lot of people don't realize that the most of the successful wireless operator or one of the most successful wireless operators today uses a technology that is only used by 13 percent of subscribers around the world.

But that's not all, inspite of all these and hence the Future of 4G will includes several interactive panels with experts who will delve into all aspects of the 4G debate. I am sure that whenever there is debate between LTE and WiMax it starts with the WiMax camp pointing out that Mobile WiMAX is the first out of the gate. Ok I agree then people argue that LTE is often considered the more evolutionary technology. The question probably isn't whether they can co-exist, they have enough common elements that it's feasible, it's whether there are enough reasons for them too.

So many times in the past including me has got into the debate of whether WiMax and LTE should or will be merged together?

In my past blog I have championed the cause of LTE and WiMax working together.
But as always there are many experts whoc belive that they ae going to work together. One of them is Peter Jarich, the research director of Current Analysys who firmly believe that LTE and WiMax are not going to merge. I can see where Pter is coming from because most of these phrases of working together are mostly biased towards politics and just from a political standpoint of getting all the parties together it's just not going to happen.
As I said in my previous blog regarding LTE and WiMax harmonization the guys have to fight it out. Now that might be bad for the carriers but it's good for the vendors who supply weapons to both sides and it's always good for consumers who get more choice.

Once thing which is quite clear though is that the presence of a rapidly maturing WiMAX ecosystem certainly has had the effect of accelerating LTE well before all the revenue potential was drawn out of HSPA and EVDO. In the past year LTE has certainly gained momentum in standards development, carrier decisions and an LTE wireless ecosystem being created. After all these significant developments in LTE analysts have started to believe that there is no reason to slow it down by merging it with WiMAX. There is, however, a reason for speeding it up to compete with WiMAX.

I can make a pretty strong argument that LTE would be at least four years later if WiMAX were not pulling it forward. WiMAX also comes with its own strengths that could add some intrigue to the battle. It's an IP standard from its base up and performs better in TDD and less mobile environments. LTE performs better in FDD and a high-user count model. That means the two could be complementary-albeit competing.

Would it be better if we had one technology and not two?

Well the debate continues……

Saturday 18 October 2008

Economic turbulence might effect funding of LTE and WiMax?

What a past few weeks we had in term of banking crises. There is no doubt that the recent turbulence in the banking sector has developed nervousness in everybody regarding the future we are going to have. I firmly believe that although the bail out has been carried by respective governments for the banks the turbulence will slip into the real economy before it starts getting better.

There is every possibility that in the near future the economic turbulence will have an impact on the funding of the projects. Some people may argue that efficient and good planning will take us through and hence the projects will not be affected. But the only question I am asking though is where the money will come from?

I do have a suspicion that as far as telecoms are concerned some of the major projects that will get affected in terms of funding will be LTE and WiMax.

We could we see analysts recalculating their projections for WiMAX and LTE soon in light of the struggling economy. There are many people out there who are putting a question mark in front of the plans that the major operators have got for LTE and WiMax. For example this week Forbes is questioning whether Sprint and the new Clearwire, which is expected to include Sprint's WiMAX network in the fold by the end of the year, can pull off a nationwide launch in a troubled economy. While Clearwire will have $3.2 billion from partners Intel, Google, Comcast, Time Warner and Brighthouse, it will need to raise an additional $2 billion to complete the network. These extra $2 billion would have been easy to generate may be a year ago but no in the current climate where there is already a shortage of money.

I am a firm believer that sometime these crises are good as this makes analysts, planning personal, designers and engineers realize to work hard and sort out the problems which they might have been complacently ignored in good times. Keeping in line with this thought, Clearwire could gain an advantage if the credit crunch lingers. Competitors AT&T and Verizon Wireless plan to deploy LTE and would likely freeze any deployments. For AT&T, such a deployment could be more than five years away as the operator doesn't seem to be in a big hurry to deploy the technology.

As I mentioned above sometimes these crises force the analysts to think hard and make sensible decisions.
For this reason I can now see that some of the companies have started taking HSPA and HSPA+ seriously which I though was always a good bet for fast mobile broadband till we get LTE. Some of operators and vendors have now reiterated their position that its HSPA and HSPA+ 3G network technology still had a lot of life left in it, and that LTE technology would not be rolled out for at least another three years and probably not on a large commercial scale for another five years.

Certainly the idea of throwing LTE on the backburner is not good for vendors that want to see operators invest in new technology soon. I am not saying this either but in the current economic climate operators and vendors can take HSPA and HSPA+ seriously do that the ARPU(average revenue per user) keep rising. If they are able to do so then the revenue generated can be used to fund the LTE/WiMax project. And once the economy starts rolling again which I’m sure will do in six months, money can pumped in heavily and vigorous plans can be drafted for LTE/WiMax.

The bigger question which arises is whether the operators can hook consumers on new technology in a tough economy. I believe they certainly can because HSPA and HSPA+ have lot to offer to consumers.

There are some analysts though which does not believe that that current economic climate will significantly impact communications usage and growth. They argue that communications are critical and relatively cheap compared to the real costly items for disposable income such as air travel, cars, home upgrades, schools, clothes, etc. They say communication revenues will probably increases and I think they might have a point here.

With the medicine provided by the governments of rich nations in terms of liquidity yet to reach to the patients, it will be a while before things start to look bit better. Let’s hope that the economy starts rolling again.

WiMAX publicity videos from Alcatel-Lucent

Alcatel-Lucent (ALU) has couple of interesting videos on youtube on WiMAX.

The first one is more of educational video showing how WiMAX is useful for everyone in everyday life:

Honestly, other technologies could be as useful as WiMAX. The other one is more of marketing presentation showing ALU offers on WiMAX.


Sunday 7 September 2008

WiMax feeling the heat, Is It slowing Down?

Ever since we started talking about LTE, WiMax was always discussed alongside LTE. Every whitepaper or article I read on LTE it has always been mentioned that WiMax in the major competitor and the one of the main motivation behind LTE.

LTE camp together with 3GPP is trying really hard to catch up with WiMax and if possible supersede it.

There is no doubt that WiMax was and is still far ahead of LTE in terms of technology. For years, WiMax has been held up as something of a panacea, a technology that would finally deliver ubiquitous and cheap wireless broadband, especially in emerging markets. WiMax camp had a great opportunity to commercialize the technology and claim it to be the technology for 4G. But in my view it’s taken so long to get off the ground that it’s in danger of being superseded specially by LTE.

I personally think that WiMax is one of the most hyped technologies in history. Please let me know if you disagree with my opinion. Every emerging technology always has some motivation and objectives behind it. WiMax is no different and one of the main objectives of WiMax was to provide consumers an excellent wireless service at a lower cost. The computer and telecommunications industries have long seen WiMax, a so-called fourth-generation (4G) wireless technology as a way of driving down telecom costs and bridging the digital divide in the poorer parts of the world.

As I mentioned above, for some reason I don’t see that WiMax camp has taken the opportunity to take the technology to its high. As cellular operators continue to ramp up their investment in 3G, the outlook for WiMax seems to be getting murkier. And the next generation of cellular technology, known as Long Term Evolution (LTE), is set to arrive in couple of year’s time, with broadband speeds many times higher than is possible on copper-based digital subscriber lines.
People might be mistaken when they think that LTE is still some time away which gives an upper edge to WiMax. This might give an indication that by the time LTE will be launched WiMax will be well developed and commercialized technology. But in this mean time mobile operators are upgrading their networks with HSPA technology which is also a good bet in terms of high speed.

Mobile operators MTN and Vodacom are already deploying 3G-based High Speed Packet Access (HSPA) networks capable of theoretical download of up to 7,2Mbit/s (nearly twice as fast as Telkom’s fastest broadband product). That is set to double again, to 14,4Mbit/s, in the next 12 months. And the 3G roadmap is promising speeds a few years from now of up to 42Mbit/s.
HSPA subscribers have grown from 11 million in August 2007 to 50 million today. HSPA subscribers are growing at a very faster rate connections per month. There are already estimated 191 commercial HSPA networks in the world and more than 740 HSPA devices.

Qualcomm has already claimed that it has placed an HSPA+ Release 7 data call at a transfer rate of more than 20 Mbps in a 5-megahertz channel.

Such a capability of telecomm giants achieving high speed would allow operators to double the data and triple the voice capacity of their networks once HSPA+ is installed. These figures are very encouraging for the industry and hence taken as a stepping stone by the operators towards commercial deployment of HSPA+ which is late this year or early next year.

These developments are definitely not very good news for WiMax and hence pushed the technology further behind. People are questioning that if we can achieve such a high data rates with HSPA+ and with LTE is round the corner then why favour WiMax, especially when WiMax seems to have more restrictions in mobility as compared to HSPA+ or LTE.

LTE, which is still some years from commercial deployment (analysts say it should start taking off in 2011 or 2012), will ultimately offer speeds of 300Mbit/s or more. If we consider all the above developments for HSPA+ and LTE don’t you think that WiMax is a little too late or is lagging behind to be a serious challenger to LTE on the mobile side?

Mobile operators invest huge amount of money when it comes to deployment of new wireless technology. People might still remember how billions were spend to gain 3G licenses. This leaves no doubt in my mind that mobile operators will influence strongly when it comes to considering the 4G technology.

WiMax camp might be optimistic as the no of subscribers is growing although at a slower rate, but it’s in 3G and later in LTE where the real action is likely to be. 3G and its related technology i.e. HSPA etc is sweeping rest of the world after already establishing itself in Europe and America. There are already commercial 3G HSPA networks in many African countries which include SA, Namibia, Angola, Nigeria, Tanzania, Kenya, Uganda, Morocco and Egypt. Libya and Mozambique will follow soon.

Even Telkom has said it has plans to build a 3G HSPA network, a startling development given that fixed-line operators have typically preferred to look at WiMax for their wireless strategies. Telkom has a limited WiMax network.

A recent BMI-T research report, written by telecom consultant Martyn Roetter, has cast serious doubts on WiMax’s potential. Roetter says cellular rivals enjoy a considerable head start, especially in mobile broadband, and it will be difficult for WiMax operators to catch up.

What I see from the WiMax growth trends is that WiMax is doing well where 3G is still a distant technology. The chances of WiMax obtaining significant market share are greatest in countries that have not yet seen the widespread roll-out of 3G cellular technologies. But even then, it has a hope only where telecom regulators have moved quickly to allocate radio frequency spectrum.

Spectrum and coverage are ultimately more significant than the “quasi-ideological and generally confusing, self-serving, and misleading statements uttered by advocates in the vendor community”, Roetter says.

Despite all these some in the industry are still optimistic about WiMax and believes that WiMax is not falling behind. WiMax is being developed within the normal industry time frame for new technologies. One of the reasons for WiMax camp to be encouraged is that the price of WiMax devices is falling sharply and from next year the technology will be built into some Intel-based laptops.

Will that be enough to save it from obscurity?

Only time will tell, but there’s little doubt that WiMax has lost some of its early edge and the hype that went along with it.

Monday 18 August 2008

4G: Where are we now.

Last month i read this news about WiMAX leading the world of 4G and last week I read about an American carrier selecting LTE as its choice of 4G technology. Since ITU has decided that they wont be using the term 4G in future and rather use IMT-Advanced or LTE-Advanced, I guess 4G is up for grabs.
The main driver for '4G' is data. Recently carriers have become agressive and started offering some decently priced 'Wireless Broadband' data plans. Rather than confuse people with HSDPA, etc., they have decided to use the term 'Wireless Broadband' or 'Mobile Broadband'. Personally both the terms have managed to confuse some people who associate Mobile Broadband with Internet access on Mobile and Wireless Broadband as broadband on WiFi.

Andrew Seybold makes some valid points in an article in Fierce Wireless. One of the things that he points out is that LTE may tout on higher data rates as compared to others, that is only possble in 20MHz of spectrum. In real world this kind of spectrum is near impossible to obtain. If the spectrum flexibility is removed than HSPA+, LTE, EV-DO Rev B and WiMAX have nearly the same data rates and performance.

For HSPA+ the existing infrastructure can be reused and a software upgrade would suffice whereas for LTE new infrastructure would be required. NTT DoCoMo has fully committed to being the first LTE network operator and others are raising their hands. He thinks that nationwide LTE networks would only be available around 2014.

While I agree with this analysis completely, I think what is going to dictate this transformation from 3G+ to LTE for the operators will be the uptake of data on a network. The biggest advantage of LTE is that it is able to operate in TDD and FDD mode. Operators that have been traditionally using FDD mode of operation will change their loyalty to TDD mode so that they can use asymmetric data transfer. This can provide more capacity in case of some special event taking place (Football finals, Reality show results, etc.) where the users are just interested in receiving information rather than sending any. For operators with paired spectrums, they can use both the band seperately in TDD modes.

Gigaom has list of American operators that are involved in 4G and the list is quite interesting:
  • AT&T: USA's largest network in terms of subscribers, AT&T plans to use LTE to upgrade to 4G, but not for a long, long time. For now it’s content with its current 3G network. It will upgrade to HSPA+ in 2009 and 2010. Eventually it will go to LTE, but won’t begin testing until 2010 or 2011 with full deployment coming after that.
  • Verizon Wireless: Verizon is already testing LTE equipment from several vendors, with plans to roll out the network in 2010 and have most of the country covered by 2012; Verizon’s would likely be the first full U.S. deployment of the LTE technology.
  • Sprint-Nextel: The outlier in the whole transition to 4G, Sprint is going with WiMAX rather than LTE. After a number of delays, the company is set to launch its network in September. By the end of the year it will join with Clearwire to operate a nationwide WiMAX network under the Clearwire brand.
  • T-Mobile: T-Mobile is still launching its 3G coverage, so its 4G networks may take a while to come to fruition. The carrier’s German parent appears to favor LTE.
  • Metro PCS: This budget carrier plans to use LTE but it doesn’t yet have a time frame for deployment, pointing out that its customers aren’t heavy data users yet.
  • U.S. Cellular: The company is unsure of its deployment plans but it would likely choose to follow the rest of the industry with LTE. As for deployment, the time frame isn’t set.
  • Leap Wireless: Recently said it had not made a decision or public comment about its 4G plans.

The picture is a bit different here in UK because all the operators are going to LTE. There may be some ISP's that may be tempted to move to WiMAX as they would get economy of scale. There is also the news of BT (the largest landline phone provider) planning to roll out nationwide WiMAX network in the 2.6GHz spectrum. If BT is able to fulfil its ambition that it could be a big win for the people.

Saturday 9 August 2008

Is WiMax Slowing Down

In the past few week it’s becoming quite interesting to know where WiMax is heading and it’s progress if at all there is any. There are so many articles which emerge everyday to say that WiMax has leaped further in terms of development in the technology and commercialization. Although I am too convinced about that but one thing about which am pity sure is that LTE has to seriously push its plans if it has to be in any sort of chance to catch WiMax.

There is no doubt that WiMax, a high-speed wireless service, is gaining momentum worldwide. Latest figures show WiMax equipment sales rose nearly 50 percent in 2007 to US$800 million. WiMAX networks have been deployed in some 80 countries with 2.2 million customers, and growth is expected to continue.

According to the WiMAX Forum, worldwide WiMAX customers will exceed 200 million by 2012, generating US$7.7 billion in equipment sales. With IEEE 802.16 ratified by the ITU last October, many operators see it as a sensible alternative to 3G mobile Internet service.
Although there is a significant divide between the equipment manufacturers when it comes to LTE and WiMax but the later is certainly pushing hard thus making life very difficult for LTE camp. Indian government’s decision of auctioning 2.3, 2.5 GHz frequency bands for broadband data has further encouraged WiMax camp.

So far, most of the excitement has been generated by equipment manufacturers such as Huawei Technologies, a member of the WiMAX Forum. Huawei is moving fast to take advantage of surging demand, mostly in Europe and North America. So far Huawei has sold 16 commercial networks and 30 trial networks, making it one of the most prolific WiMAX vendors in the world.

Huawei also is engaged heavily in WiMAX R&D activity: It has 1,200 engineers dedicated to WiMAX product development; it owns 100 WiMAX- related patents, more than any other company. Huawei is also developing WiMAX terminals which are expected to become available for sale later this year. The handsets reportedly will work in dual-mode with CDMA, GSM and 3G (WCDMA).

ZTE, another Chinese equipment maker and a senior member of the WiMAX Forum, began OFDM research in 1998. It projects sales of WiMAX equipment will reach that of CDMA by 2011 (estimated US$700 million). ZTE is more enthusiastic about WiMAX and it predicts WiMAX will make up 20 percent of the global wireless market by the end of 2009 after commercial handsets become readily available later this year.

When all the manufacturers are getting excited and trying to run as fast as they can operators are mum whether they will jump on the WiMAX bandwagon. Vodafone, T-Mobile and AT&T are yet to announce any significant trials on WiMax. There are no signs of any massive deployment of WiMax especially in China and India which are considered as the biggest WiMax market. China Mobile and China Unicom show no signs of massive deployment or commercial service after small trials two years ago in a half-dozen cities, including Beijing, Shanghai, Wuhan and Shenzhen. Most trials employed 802.16d (fixed access) at 3.5 GHz, a temporary spectrum band for experiment. Most trials used WiMAX as backhaul for businesses to transmit data and video in a campus environment. It is premature to assume large-scale deployment will follow, at least in the immediate future, because the industry is consumed completely by restructuring, which, in addition to changes in organization and personnel.

China Mobile, for example, is carrying the torch of TD-SCDMA, a home- grown, 3G wireless standard which the government hopes to become a winner someday. For China Mobile, TD-SCDMA is very much a political mandate and it has no option but to succeed. If this holds out, it is natural for the operator to adopt some kind of LTE for TD-SCDMA, an evolutionary platform for faster speed and more profitable service.

Questions remain, Operators must weigh WiMax’s potential gains against the cost of deploying regional or national networks, and there is no clear-cut answer. While WiMAX can offer significant speed to fixed and mobile devices which are conducive to more bandwidth-sensitive services like video and TV broadcast, the key hurdle is scale. As tests show, a typical 802.16e base station delivers 30Mbps, but actual speed can whittle down to 1.2Mbps or lower when “fully loaded” with access.

If speed is compromised, cost will become a serious concern. According to estimates, operator capex for WiMAX will be 20 percent to 50 percent higher than for HSDPA, a software-enabled overlay for sending data over 3G networks. At higher frequency, say 3.5 GHz, the number of WiMAX base stations must increase, as many as 50 percent more than for HSDPA, to cover the same area without signal degradation. This is the last thing operators want after already plunking down billions on 3G networks.

So far operators have focused mainly on network and handset performance and not on services which can have a negative effect on initial growth. Despite all the hype, it is not clear if WiMAX will create the miracle equipment vendors want to see especially in China, since there simply is a lack of driving force among the governments, operators and the public. If anything, WiMAX will complement 3G especially in data service for high- end customers, enterprises and government agencies, but its role as a public service will be limited.

Sunday 27 July 2008

Adaptive Antenna System

Whenever we talk about the evolution of new technology in telecoms world one thing which always occupy the prominent position is the spectral efficiency. The success and efficiency of any wireless system depends on the spectral efficiency.

What is spectral efficiency though?

Spectral efficiency can be defined as bits/seconds/Hz/cell. It measures how well a wireless network utilizes radio spectrum and also determines the total throughput each base station (cell) can support in a network in a given amount of spectrum.

There is no doubt that if a new air interface is to be build it should be built from the ground up to be optimized for spatial processing. Spectral efficiency directly affects an operator’s cost structure. For a given service and grade of service, it determines the following:
  • Required amount of spectrum (CapEx),
  • Required number of base stations (CapEx, OpEx),
  • Required number of sites and associated site maintenance (OpEx), and,
  • Ultimately, consumer pricing and affordability

Spectral efficiency will become even more important as subscriber penetration increases, per-user data rates increase and the as quality of service (esp. data) requirements increase.

There are so many elements for design to achieve high spectral efficiency. Adaptive Antenna System (AAS) is one of the methods to achieve high spectral efficiency.

Adaptive Antenna System (AAS) provides gain and interference mitigation leading to improved signal quality and spectral efficiency.

The use of adaptive antenna systems enables the network operators to increase the wireless network capacity, where such networks are expected to experience an enormous increase in the traffic. This is due to the increased number of users as well as the high data rate service and applications. In addition, adaptive antenna systems offer the potential of increased spectrum efficiency, extended range of coverage and higher rate of frequency reuse.

Adaptive antenna systems consist of multiple antenna elements at the transmitting and/or receiving side of the communication link, whose signals are processed adaptively in order to exploit the spatial dimension of the mobile radio channel. Depending on whether the processing is performed at the transmitter, receiver, or both ends of the communication link, the adaptive antenna technique is defined as multiple-input single-output (MISO), single-input multiple-output (SIMO), or multiple-input multiple-output (MIMO).

Multipath propagation, defined as the creation of multipath signal paths between the transmitter and the receiver due to the reflection of the transmitted signal by physical obstacles, is one of the major problems of mobile communications. It is well known that the delay spread and resulting inter symbol interference (ISI) due to multiple signal paths arriving at the receiver at different times have a critical impact on communication link quality. On the other hand, co-channel interference is the major limiting factor on the capacity of wireless communication systems, resulting from the reuse of the available network resources (e.g., frequency and time) by a number of users.

Adaptive antenna systems can improve link quality by combining the effects of multipath propagation or constructively exploiting the different data streams from different antennas. More specifically, the benefits of adaptive antennas can be summarized as follows:

  • Increased range/coverage: the array or beam forming gain is the average increase in signal power at the receiver due to a coherent combination of the signal received at all antenna elements. The adaptive antenna gain compared to a single element antenna can be increased by an amount equal to the number of array elements, e.g., an eight element array can provide a gain of eight (9 dB).
  • Increased Capacity: One of the main reasons of the growing interest of adaptive antennas is the capacity increase. In densely populated areas, mobile systems are normally interference-limited; meaning that interference from other users is the main source of noise in the system. This means that the signal to interference ratio (SIR) is much larger than the signal to thermal noise ratio (SNR). Adaptive antennas will on average, increase the SIR. Experimental results report up to 10 dB increase in average SIR in urban areas. For UMTS networks, a fivefold capacity gain has been reported for CDMA.
  • Lower power requirements and/or cost reduction: Optimizing transmission toward the wanted user achieves lower power consumption and amplifier costs.
  • Improved link quality/reliability: Diversity gain is obtained by receiving independent replicas of the signal through independently fading signal components. Based on the fact that one or more of these signal components will not be in a deep fade, the availability of multiple independent dimensions reduces the effective fluctuations of the signal.
  • Increased spectral efficiency: Spectral efficiency is a measure of the amount of information –billable services- that carried by the wireless system per unit of spectrum. It is measured in bits/second/Hertz/cell, thus it includes the effect of multiple access methods, modulation methods, channel organization and resource reuse (e.g., code, timeslot, carrier). Spectral efficiency plays an important role since it directly affects the operator cost structure. Moreover, for a given service and QoS, it determines the required amount of spectrum, the required number of base stations, the required number of sites –and associated site maintenance-, and ultimately, consumer pricing and affordability. Equation (1) shows a simplified formula to estimate the required number of cells per square kilometer. (the offered load is in bits/seconds/km2).
  • Security: It is more difficult to tap a connation, since the intruder has to be position himself in the same direction of arrival as the user.
  • Reduction of handoff: there is no need for splitting the cells for the sake of capacity increase, and in consequence less amount of handoff.
  • Spatial information: the spatial information about the user would be available at any given time, which enables the introduction of Location Based Services.

In addition to the above-mentioned benefits and liken any other systems AAS has got it’s own drawbacks as well. One must point out the following drawbacks (or costs) of the adaptive antennas:

  • Transceiver Complexity: It is obvious that the adaptive antenna transceiver is much more complex than the conventional one. This comes from the fact that the adaptive antenna transceiver will need separate transceiver chains for each of the array elements and accurate real-time calibration of each of them.
  • Resource Management: Adaptive antennas are mainly a radio technology, but they will also put new demands on network functions such as resource and mobility management. When a new connection is to be set up or the existing connection is to be handed over to a new base station, no angular information is available to the new base station and some means to “find” the mobile station is necessary.
  • Physical Size: For the adaptive antenna to obtain a reasonable gain, an array antenna with several elements is necessary. Typically arrays are consisting of six to ten horizontally separated elements have been suggested for outdoor mobile environments. The necessary element spacing is 0.4-0.5 wavelengths. This means that an eight-element antenna would be approximately 1.2 meters wide at 900 MHz and 60 cm at 2 GHz. With a growing public demand for less visible base stations, this size, although not excessive, could provide a problem.

An Adaptive Antenna System (AAS) can focus its transmit energy to the direction of a receiver. While receiving, it can focus to the direction of the transmitting device. The technique used in AAS is known as beamforming or beamsteering or beamshaping. It works by adjusting the width and the angle of the antenna radiation pattern (a.k.a. the beam). Combined with multiple antennas in the Base Station (BS), AAS can be used to serve multiple Subscriber Stations (SSs) with higher throughput. A technique known as SDMA (Space Division Multiple Access) is employed here where multiple SSs that are separated (in space) can transmit and receive at the same time over the same sub-channel.

AAS also eliminates interference to and from other SSs and other sources by steering the nulls to the direction of interferers.AAS is feature suits very well for LTE and it is an optional feature in WiMAX as it yet to be included in WiMAX certification. But due to its effectiveness in improving performance and coverage especially in Mobile WiMAX case, many vendors integrate AAS capability into their products.

Saturday 19 July 2008

LTE and WiMax Harmonization

Everytime I decide to move away with the LTE and WiMax subject I just find something new to tell you guys. Recently I have found that some more debate is emerging from the LTE and WiMax camps regarding the harmonization between them.
As I said from the very beginning, in my opinion the harmonization of WiMAX and LTE makes good sense for the development of the industry. There is enough evidence that the two camps are interestedand participants from both the WiMAX and LTE camp and IEEE and ETSI 3GPP standards organizations have recognized the need to collaborate on development of communications.
You might remember from my previous blogs that outgoing CEO of Vodafone, Arun Sarin was one of the first to raise the issue openly of the two camps having a future together. Vodafone is among operators that have called for the merging of WiMAX and LTE because this will reduce conflicts and costs for the industry. The long-term trends in technology, regulation, ecosystem consolidation and globalization contribute to the rationale that wireless systems should strive to achieve common air interfaces where feasible. The primary obstacle to achieving harmonization of WiMAX and LTE is simply the commercial self-interests that prevent a common push forward.
Intel CEO Paul Otellini and Sean Maloney, head of Intel's sales and marketing, have called for harmonization between WiMAX and LTE, pointing out the goals of unified broadband communications and common use of technologies. But everything which is coming out of Intel in terms of two technologies, it clearly suggests that Intel will eventually provide combined support regardless of whether the standards groups achieve official harmonization or not. I am sure that Intel will provide a multi-mode WiMAX plus LTE chipset. Maloney came close to saying this but he preferred to say this
"We don't have any plans to do that yet; it would certainly be a nice long term goal."
I have no doubt that harmonization has become a hot topic because of heightened competition between WiMAX and LTE for a role in molding development of the next generation of wireless, 4G. While I do not think the current stage of development of WiMAX or LTE qualifies as 4G, both systems are frameworks for evolution to 4G.
There are several factors within wireless developments to compel harmonization. Following are some of them
-Pursuit of IMT-Advanced as the path to 4G
-Both existing 3G, ‘fixed' and new spectrum will be consolidated
-Multiple scale and application support
-Common SDR (Software Defined Radio) base stations
-Common Integrated Circuits
-Use of 80 percent to 90 percent common technologies
-Globalization of R&D
-Need for reduced cost for embedded applications & digital divide
-Harmonization of wireless standards is a stated goal of 3GPP
-Common ‘modular concept' for harmonization across systems

If we take a ‘30,000 foot perspective' at the evolution of communications, it becomes clear that arriving at common air interfaces is now not only feasible but also a desirable result. Leading wireless suppliers have consolidated in order to leverage content, services and applications across networks. Technology used in WiMAX and LTE are converging because both camps have come to similar conclusions on the technologies needed to form the next-generation evolutionary framework. In brief, the framework includes OFDMA, MIMO and Adaptive Antenna Systems (AAS) smart antenna technologies, and IP-based adaptive network architecture. The few significant differences between WiMAX and LTE are surmountable and can fit within the capabilities of increasingly adaptive radio techniques and smart IP-based network developments.
Further, societal demands for digital inclusion, a growing need for education, enterprise and government communications, harnessing of communications as an alternative to travel, and better use of spectrum resources compels a unified approach to wireless.
While all these talks of harmonization continue there are still some in the industry who favors one over another. This was evident when recently Sprint announced that it’s withdrawing from the Next Generation Mobile Networks (NGMN) Alliance, a group of global mobile operators that banded together last year to push for a common vision for networks and technologies beyond 3G. The operator was a founding member of the NGMN. Sprint said it ended its relationship with the NGMN Alliance after the group chose to endorse LTE (Long Term Evolution) for 4G. Sprint spokesman John Polivka said the NGMN was supposed to endorse the co-existence of various technologies without favoring one over another. In fact, he said, technology neutrality was a key tenet of the NGMN to make sure it didn't duplicate the work being done in existing standards bodies.
"Sprint was disappointed that NGMN shifted from its original technology-neutral stance. We respectfully withdrew our membership from the organization due to the change in direction," he said. "We are enthusiastically continuing with our plans to work with our burgeoning ecosystem and launch a WiMAX network in select U.S. cities beginning in the third quarter with expansion throughout 2009 and beyond."
Founding members of the NGMN Alliance include China Mobile, NTT DoCoMo, Vodafone, Orange, KPN and T-Mobile, all of whom back LTE. A quick look at the list of the 18 operator members on the NGMN Alliance website shows the majority of the operators come from the WCDMA community, whose 4G path is LTE.
Another evidence of favoring one over the other occurred when in-flight communications provider Aircell announced that the future of its mobile broadband network will be based on LTE (Long Term Evolution).
Today, the company's Gogo service uses CDMA 1xEV-DO Rev. A technology, which enables the company to offer its air-to-ground data service at a data rate of more than 12 Mbps peak to Gogo-equipped aircraft. By the end of 2009, further advances to EV-DO will enable Aircell to deliver a raw data rate of up to 22.7 Mbps to aircraft. And by the start of 2011, Aircell expects to deploy its 4G LTE network, which will enable a throughput of up to 300 Mbps to aircraft.
The company says LTE will enable in-flight services such as hi-definition and interactive television as well as multi-player gaming. Aircell said it also chose LTE as a way to future-proof its air-to-ground technology. Airlines will also benefit from LTE because the technology will allow them to enhance their operations by offering applications such as high-resolution weather to the cockpit, the company said.
The company's customers so far include Virgin America and American Airlines

Ron Resnick, president of the WiMAX Forum, has said that the harmonization between WiMAX and LTE is "really up to the operators if that's what they want to do." That is the deciding factor that will determine to what extent WiMAX and LTE harmonize within the standards groups. Make no mistake, the technologies, ICs, devices, and systems are in the process of converging. Whether this occurs harmoniously or with excess rancor is up to the industry.