Showing posts with label Femtocells. Show all posts
Showing posts with label Femtocells. Show all posts

Monday, 8 August 2011

Radio-over-Fiber (RoF): The existing alternative to Femtocells

Recently while going through NTT Docomo Technical Journal, I came across an article on Radio over Fibre. This is the first time I have come across RoF but apparently this is a common way to provide indoor coverage before Femtocells.
My intention here is not to compare this with Femtocells as I can think of advantages and disadvantages of both of them.


I found the following extract in the book Femtocells: Technologies and Deployment:

Active Fibre DAS (Radio over Fibre)

Active fibre DAS is the most efficient in term of performance. Optical fibres are used to make the link between the MU and the RU. They can cover very long distances (up to 6 km) and support multiple radio services. With such a system the RU directly converts the optical signal into radio signal and vice versa. The other advantage is that optical fibre is very cheap and easy to install. Radio over fibre is now the most common technique used for indoor radio coverage. As detailed in [16], radio over fibre is today the optimal solution to extending indoor coverage, because it provides scalability, flexibility, easy expandability, and also because the signal degradation is very low compared with DAS using standard connections.


The following is from Wikipedia:

Radio over Fiber (RoF) refers to a technology whereby light is modulated by a radio signal and transmitted over an optical fiber link to facilitate wireless access. Although radio transmission over fiber is used for multiple purposes, such as in cable television (CATV) networks and in satellite base stations, the term RoF is usually applied when this is done for wireless access.

In RoF systems, wireless signals are transported in optical form between a central station and a set of base stations before being radiated through the air. Each base station is adapted to communicate over a radio link with at least one user's mobile station located within the radio range of said base station.

RoF transmission systems are usually classified into two main categories (RF-over-Fiber ; IF-over-Fiber) depending on the frequency range of the radio signal to be transported.

a) In RF-over-Fiber architecture, a data-carrying RF (Radio Frequency) signal with a high frequency (usually greater than 10 GHz) is imposed on a lightwave signal before being transported over the optical link. Therefore, wireless signals are optically distributed to base stations directly at high frequencies and converted to from optical to electrical domain at the base stations before being amplified and radiated by an antenna. As a result, no frequency up/down conversion is required at the various base station, thereby resulting in simple and rather cost-effective implementation is enabled at the base stations.

b) In IF-over-Fiber architecture, an IF (Intermediate Frequency) radio signal with a lower frequency (less than 10 GHz) is used for modulating light before being transported over the optical link. Therefore, wireless signals are transported at intermediate frequency over the optical.


Access to dead zones

An important application of RoF is its use to provide wireless coverage in the area where wireless backhaul link is not possible. These zones can be areas inside a structure such as a tunnel, areas behind buildings, Mountainous places or secluded areas such a jungle.


FTTA (Fiber to the Antenna)

By using an optical connection directly to the antenna, the equipment vendor can gain several advantages like low line losses, immunity to lightening strikes/electric discharges and reduced complexity of base station by attaching light weight Optical-to-Electrical (O/E) converter directly to antenna.


Thursday, 4 August 2011

Detailed presentation on Femtocell Security from Black Hat 2011

Femtocells: a Poisonous Needle in the Operator's Hay Stack
View more presentations from Zahid Ghadialy
Presentation available to download from here.
Detailed write-up on: Exploiting the Ubiquisys/SFR femtocell webserver here.
My earlier blogpost 'Femto Hacking in UMTS and LTE' here.

Monday, 25 July 2011

Femto Hacking in UMTS and LTE

Couple of weeks back, The Hacker’s Choice (THC) made available some documents about how the Vodafone's (UK) Femtocell (a.k.a. SureSignal) is unsecure and can be hacked. Everyone seemed to jump on this bandwagon with some news articles even sounding like the whole Vodafone network has been hacked and hackers may be sending messages and making calls via your phone number.

In the end it came to light that the problem was fixed over a year back when Vodafone was made aware of this problem. THC is still arguing that there is an architecture fault and the Femto can be compromised.

As a result I decided to think about what could happen if the Femtocell is hacked.

Lets take case of UMTS Femtocell. A simple network architecture with femtocell (oficially known as Home NodeB) is as follows:

As you can see, the signalling over the air interface is encrypted and integrity protected. If a hacker is able to get into the Femto and able to listen to all the packets using some tool like WireShark, he would be able to get hold of the Ciphering and Integrity Keys as they come in cleartext in the RANAP Security Mode Command message.

It wouldnt be difficult to have a device that can listen to the conversations once provided with this keys. In fact if the hacker is able to listen to the messages, there is no reason he cannot stick his own messages at the right interval (when a voice call is ongoing) to send SMS and would appear that the message actually went from the phone number. Note that this message would be inserted in the Home NodeB and would be a NAS message. The end user would generally never find out that a message has been sent on behalf of his phone.

One thing that should be remembered though is that the phone would have to be in the range of the Femtocell and connected successfully to the network (via the Femto). One question someone may have is that can I not reverse engineer the key so that I can clone the SIM card. Fortunately for us, this is not easily possible. There are multiple levels of protection and generally it would be difficult to get the algorithms for generating the key. Also it should be noted that the authentication algorithms are confidential and only the operators know the algorithm.


Now lets look at the LTE Femtocell (a.k.a. Home eNodeB) as shown below:

One of the differences you may notice is that the signalling from Femto to the Core Network over S1 is encrypted and Integrity Protected. In case of the LTE Femto, there are multiple keys and only the required key (Kenb) is provided to the Femto. See the key hierarchy below:

Source: RedYoda

This would sound like an ideal protection from the end user perspective but some of the problems still remain. If the hacker can get hold of the Kenb which is sent in cleartext over the S1 interface via Initial Context Setup Request message then he could easily use it to listen to the packets. Since there is no voice support as of yet in LTE, it would only be the packets that the hacker can listen to.

As you may notice, there is now an Integrity and Ciphering on the S1 interface for the UE messages, the hacker cannot get hold of the Kasme or the master keys K, CK and IK. This means that he cannot insert rouge messages that would for example send unsolicited SMS on behalf of the user as he would be able to do in case of UMTS.

There is a small caveat though. There are multiple Ciphering and Integrity algorithms defined in the standard. No ciphering is defined as eea0 algorithm. In Release-8 of LTE, there was no possibility to have Integrity switched off as there was no eia0 algorithm defined. In Release-9 though, the new eia0 has been defined which means that the network can set the Integrity to NULL. I am sure that the network would not want to do so as it makes absolutely no sense but the hacker can force it to do so.

When the Network requests the UE to send the capability information, the hacker can force it to say that it only supports eia0 and eea0 which would mean that the integrity and ciphering in the call would be off. To be honest, this is quite a difficult thing to do in real time and also the network would not accept a UE that does not support other Integrity and Ciphering algorithms.


3GPP has already forseen these kind of threats that could be affecting the networks in the future when they roll out the Femtocells. As a result they have produced 3GPP TR 33.820 that lists all the possible threats and the best practices that can help to minimise the chances of the network being compromised. If that document is too big and technical, you can go though this presentation as it summarises some of the problems.

Feel free to comment or correct any mistakes that you think I have made.

Tuesday, 19 July 2011

Dual-Mode and Multi-Mode Femtocells

Came across this slide in one of the presentations from MWC.


The Dual-Mode and maybe Multi-Mode solution (in future) may be very useful, not only from the point of view that it can serve LTE as well as 3G mobile devices but in case of a LTE mobile where for voice calls the UE may have to fall back on 3G network, if there is no 3G coverage then there would be no voice communication possible.

One of the ways to do have a voice communication in the initial phases of LTE is CS Fallback (CSFB). CSFB is possible by the UE establishing the call on UMTS or GSM network. If for some reason the coverage on those networks is non-existent then having a dual-mode femtocell can be really helpful as it would seamlessly transfer the voice call on the 3G.

Hopefully in the future when VoLTE is here these problems would be solved automatically.

The main problem that I can see with this Dual-mode or Multi-mode solution is that the operator would have to be supporting both Small Cells solution across both the networks and I guess they would be slightly expensive.

Sunday, 26 June 2011

Second hand report from the Femtocell World Summit 2011 (#FWS11)

Here is a summary from the Femtocells World Summit 2011 that I have compiled from different blogs and twitter. I was unable to be there, due to the expense, location and timing of this event it simply wasn’t feasible for me to attend. I am also disappointed that the organisers are not more welcoming of bloggers and do not understand how valuable our participation can be for the summit. Peronally, I would have taken a few pics of the exhibition, as I have done in the past, as it would have provided a better idea about the event to people in different parts of the world. Anyway, summay as follows:


DAY 1 began with Simon Saunders from the Femto Forum. Some of his points:

60% of consumers are interested in femtocells now Another interesting statistic was that there are now more 3G femtocells in the world than there are 3G macrocells, which again agrees with data stating that 60% of operators think small cells are more important than macrocells in the success of LTE.

According to the Ubiquisys blog: Simon’s thoughts are best summed up with a sort of rallying cry he came up with: “Our cells are small but our goals are not”!


This was followed by, Thilo Kirchinger, Principal Product Manager forVodafone Group. He discussed Vodafone’s operational stance on femtocells and small cells, and during which confirmed that Vodafone would indeed be launching LTE femtocells.

Thilo also spoke about how he sees femtocells integrating and being used by people in home environments. For example, instructions for home femtocells should be as simple, with as little technical information as possible, limiting potential confusion for the end user, while voice communications is still the biggest draw for this kind of residential femtocell (despite the fact that people tend to use a lot of data for things like app browsing when at home).
There are now 9 Vodafone subsidiaries with commercial femtocell service – almost a third of the total – and more are to follow shortly.
Research showed that some 34% of the UK either have insufficient or unsatisfactory indoor mobile coverage and Wi-Fi only partly solves the issue.
In summary, he'd like to see accelerated standardization of the Iu-h interface, for the femtocell supplier ecosystem to start engaging with the Connected Home industry and for femtocell costs to reduce further.
David Chambers of thinkfemtocell.com asked how operators, such as Vodafone, with strong brands of being the best mobile network and coverage could reconcile asking customers to pay for a box to fix poor coverage problems. Thilo felt that femtocells were complementary (especially for growing indoor use) and by offering both (ie great outdoor macrocell coverage plus great indoor femtocell service) it gave them competitive advantage. Another question related to 3rd party broadband internet – he reported that this hadn't been a problem, especially where customers conduct a speed test as part of the pre-sales process.


Telecom Italia’s Ferruccio Antonelli took the third slot of the day with a presentation focusing on the company’s commercial trial and proposed launch of femtocells in Italy.

Telecom Italia Mobile (TIM to the locals), has always been a bit of a trendsetter in the mobile industry and is one to watch. They have the highest penetration rate and smartphone takeup of any European country. They will launch femtocell services next month (the precise date is commercially withheld), with Alcatel-Lucent providing two sizes of femtocell (seems very similar to Vodafone products).
It won't be mandatory to use Telecom Italia broadband – any third party wireline/cable broadband can be used. While the pricing also can't be revealed, their billing system will be flexible enough to offer different prices when customers are using their "femtozone" at home.
It sounds like it’s been a time of experimentation in Italy for femtocells thus far, but signs are looking good, with Ferruccio stating that femtocells will see launch in the second half of 2011. There was also some discussion on Twitter stemming from Telecom Italia’s idea of a ‘femtozone’ tariff or simply keeping pricing the same.
A major issue for their implementation was the regulatory requirement to know if the femtocell has been moved (so that emergency services go to the right address) – this is checked by ensuring that at least one external macrocell ID is the same as when the unit was first installed and/or that the Telecom Italia broadband IP address matches.
Unusually, TIM want to have SIM cards to authenticate their femtocells – so for example faulty femtocells can be replaced and by swapping the SIM card would automatically reconfigure for that customer.

Some insights from South Korea was provided by Samson Tae-Yong Kim from SK Telecom, whose presentation focused on using femtocells for data offload.

Of particular note was the disparity raised by Kim in terms of data usage between different types of phone. For example, some smartphone users are consuming as much as 1 gig of data on an ‘all-you-can-eat’ plan in the same amount of time that it would take a feature phone user to consume 10 megs. It’s also worth mentioning at this point that 20% of mobile phone users in South Korea have smartphones, and this number is sure to grow.
South Korea Telecom (SKT) plan to deploy some 10,000 public hotspots before the end of the year, many equipped with both Wi-Fi and cellular. They've previously used a lot of repeaters to ensure excellent (voice) coverage, but now need to bring in heavy additional capacity and higher speeds.


Alcatel Lucent: Steve Kemp looked at how data usage is now ballooning – indeed, that we are now “nearing the practical limits of information theory” –
This is a generation that is watching 2 billion Facebook videos a month and 2 billion YouTube videos a day.
Alcatel-Lucent expects mobile traffic growth to be in the order of 30x in the next five years.
Just look at the iPad – users consumer twice as much data (and signalling) as the average iPhone user.
What’s the problem? Signal to noise. As Claude Shannon at Bell Labs in 1948 theorized, a network is limited intrinsically by the noise generated by the media and the users. As you get more users, it degrades the overall capacity of the network.
LTE, despite being more spectrally efficient than 3G, has a theoretical capacity limit, under Shannon’s Law, of 3.5 mbps per hertz.
The answer to this inescapable fact is to make the cell size smaller so that spectrum is more efficiently used. And use beam forming to focus spectrum where you need it, away from interference
Kemp then moved onto the business case for femtocells. You need initially to improve customer retention because keeping customers is a whole lot easier than gaining new ones.
Femtocells result in a 60% downlink improvement, and a 26% uplink improvement. With lower latency, customers are happier with their voice calls at home and churn less. You can build a business case for home femtocells on this alone.
Metro femtocells have even more compelling business case. The more traffic is offloaded onto small cells, the users on macro cell also see a service improvement.
Steve also raised a point that kept reappearing through the morning: iPads (and tablets in general) are far more data hungry than iPhones/smartphones, which is certainly food for thought when considering the sudden surge in popularity of these devices.
Alcatel-Lucent also announced their femtocell application developer kit, which is based on the recently published Femto Forum femtocell API specification. Already 23 developers have signed up to use it, with the first application to be made available by Telecom Italia when they launch.



As the morning progressed, it was the turn of Nigel Toon, CEO at Picochip, to present his thoughts and findings on the impact of femtocells on network performance and capacity.

Nigel noted that voice communication is still one of the most important reasons why people select a carrier. Nigel also raised the point that no one really knows by how much mobile data traffic usage is expanding (or due to expand), with various different proposals raised during day one of FWS 2011 alone.
Mobile data traffic exploding – you guess by how much. Is it 30x, 50x or even 1000x ?
Problem is carriers capex can’t grow at 1000x
Currently carriers spend, on average, 20% of their revenues on capex. And the cumulative amount of capex is increasing 8% year on year).
Need to serve customers more efficiently and at a lower cost.
Today a user in the middle of macrocell might only experience 40kbps. Tomorrow, with femtocells, the user can enjoy 8mbps while increasing the performance (less crowing on the macro) to 170 kbps.
The key to low cost deployment is self-organizing, self-configuring, interference management and remote management.
Picochip reaffirmed the issue of replacing repeaters with additional capacity, suggesting that rationing wasn't the right answer for customers who have grown to love data access. The web will only increase reliance on data connectivity and network operators will need to respond by building out a new network layer to meet demand.


Nitin Bhas from Juniper Research discussed the principals of mobile data offload and onload, where ‘offload’ means data migration from mobile to fixed, and ‘onload’ vice-versa. The spectre of tablets such as the iPad and smartphones being data hogs was once again raised during Nitin’s presentation, as was the important of the ‘offload’ of data due to this very reason.Mobile data traffic from smart phones, tablets and other devices to grow to 14,211 petabytes by 2015. This will be equivalent to 18 billion video downloads. By 2016, 63% of this will be offloaded to Wifi or femto.


Bill Chang, chief planning and strategy officer, UMobile explained that UMobile is a new challenger in Malaysia, challenging three well entrenched incumbents Digi (leader in price), Maxis (leader in products) and Celcom (leader in coverage.)
Malaysia has 120% penetration, expected to rise to 150% within 5 years. 28 m population.
70% of market revenues come from 8% coverage area. Highly urbanised. So when UMobile launched in 2007, made sense to target where 70% of the revenue was coming from.
Currently has 1200 node Bs and roaming onto 2G partner network.
Price is in decline in Malaysia, ARPUS are falling for voice. The market has reached revenue saturation.
Operators need data centric growth and they need it to be low costs business case. Makes sense to use femtocells. (In Malaysia, smartphones make up 65% of new phone sales)
Umobile has limited capex, so trialling femtos with Alcatel-Lucent. Using home and hotspot femtos.
Plan to launch femtos commercially. Will improve indoor coverage, data offload, reducing roaming costs (because they have to pay their 2G partner) and bundled services.
Malaysian govt has target of 75% BB penetration by 2016.
“Its a no brainer for us to give away femtos for free”
However their strategy is somewhat hampered by a local regulation (tax) of around US$600 per cellsite – not really significant for macrocells, but a serious problem for thousands of femtocells.


Continuous Computing launched their "Femtotality" software product. No longer limited to just the protocol stacks, they've invested an additional 150 man years in their application layer (I believe this figure includes an acquisition, otherwise their 200 staff would have been working a lot of overtime) and now offer SON (Self Optimisation), remote management and configuration features too.


NTT DoCoMo was able to restore cellular service after the earthquake/tsunami in just 6 weeks after 4,900 cellsites were put out of service in the Tohoku region alone - femtocells were part of the solution. They plan to switch off their 2G service next year and have already launched LTE. They intend to deploy LTE femtocells as soon as possible.


Finally, Broadcom’s Shlomo Gadot gave a provocative presentation where he outlined a compelling vision for femtocell technology. He sees no reason why Wi-Fi hardware should be cheaper than femto in future, and named integration as a key trend. Following this trend, Shlomo gave more details of the forthcoming integrated WiFi/Femto/ADSL residential gateway, the first of its kind, announced by Ubiquisys earlier that same day.


DAY 2

Dr Alan Law of Vodafone Group talking about femtocells beyond the home.

Vodafone’s vision started with consumer cells, and great things are happening both at home and abroad with this arm of their femtocell operation. But where do you take femtocells when looking beyond residential?
Vodafone has been trialling its enterprise and rural cells, and some interesting information emerged when Dr Law recounted some statistics from their rural and enterprise test deployments. The amount of dropped calls noticeably decreased when voice and data was offloaded onto the femtocell – which means better quality of service for Vodafone’s customers. There are still some challenging aspects to rural deployment such as IP transport and power locations, but on the whole results were positive.
Vodafone’s enterprise femto trials have also been successful, with data services noticeably enhanced in enterprise environments when femtocells were brought into the mix. The company’s ‘Metrozone’ concept would provide extra network capacity for data offload in denser urban areas.


Next there was a fascinating presentation from Rick Vergin, CEO of Mosaic Telecoms. He represents a rural telco, and outlined the problems of serving customer who live predominately in farmland or forest. It is desperate to deploy femtocells to not just plug gaps, but create coverage for the first time. Cellular coverage is the chief concern: macrocells can provide coverage to population centers (towns over 200 people) and microcells can support where people gather regularly (schools, for instance). But thousands live outside this coverage area.

First problem is geography: most of Mosaic’s customers live towns with 200 people up to a small city with 9000. But the 9000 square mile coverage area within its 3G license, comprises mostly farmland or forest – and potentially 100,000 people.
Mosaic runs 3G in band IV, a relatively underused part of the spectrum from a global perspective. This has caused unprecedented problems with femtocell vendors, with Airvana, Technicolor and Arcadyan all contracted only to subsequently drop out one at a time. Finally, with the guidance of Nokia Siemens, Ubiquisys was selected.
Farmland is not so bad, but forest is very challenging for the Mosaic’s 35 macro cell sites. CEO Rick Vergin lives 200m from a main road, and 2 miles from the nearest macro cell. On the road, he has line of site and 4 bar coverage, at home he barely has 1 bar coverage. Many of the potential customers in their licensed area have no coverage.
The femtos will bring coverage to people with currently little or no coverage. Moscaic has no intention to use femtos to create ubiquitous coverage – that would be way too expensive. But what they can do is give subscribers coverage most of the time: at home, at school, at the cafe. It will only be on the journeys between that they may have no bars.
The rural customers of Mosaic will also benefit from LTE because it will be used to backhaul the femto traffic and also provide broadband access for the first time (remember many of these properties will be far away from an exchange and may not use satellite or microwave. Mosaic will use the 750MHz LTE for residential broadband access, and bundle VoIP and femto/cellular with it. (750MHz is much more spectrally efficient than its 1700/2100 MHz 3G spectrum).
This is a great case study for not just the 1000 rural US telco but for any operator that either operates in the rural segment or has universal access obligations.



Peter Agnew of Colt Telecom took to the stage to present his views on what it takes to overcome the barriers to launching a femtocell service through fixed and mobile collaboration. If that sounds like a bit of a mouthful, all will become clearer in a minute!

Colt Telecom is a large pan-european fixed line operator, working in 21 countries with organisations such as major banks. Peter proposed that in working together with a fixed line operator such as Colt, mobile operators will have an ally in femtocell deployment, aiding connectivity, quality of service and increasing the mobile operator’s access to enterprises.
In essence, what Peter and Colt are proposing is ‘femto-as-a-service’ (‘FaaS’), which was met with some figurative nods of approval on Twitter. Peter finished his presentation by noting that for something like FaaS to work, self-organising network technology would almost certainly need to play a role in such a deployment.
It’s an important development for operators wanting to take their first steps in femto, which often starts with the low-risk bit low-volume enterprise route. This solution is the first to remove the barrier of high up-front gateway and integration costs, and the subsequent reliance on volume in the business case.
Another approach, and its not one that COLT said it would necessarily be offering, is to provide in-building installs (as long as there is not radio planning). It makes sense for a business telco with experience of firewalls, LANs and so on to assist both enterprise and mobile operator in this area.
In dense metropolitan areas, most subscribers are sitting within an office. It makes sense to bring coverage closer to these users, and not charge the enterprise for this (either for the access points or in-building cabling). It improves the coverage of the enterprise subscribers and for everyone else in the macro – both are sufficient incentives for the mobile operator to foot the bill.
However, more bandwidth available means more consumed. COLT asks, do mobile operators have the fixed-line infrastructure and core-network to cope with the increase in backhaul requirement?


Cisco’s Mark Grayson, spoke about mobile offload architectures. One of Mark’s main points that resonated with the Twitter audience following the #FWS11 hashtag was that the cost for networks is dealing with the non-uniform peaks in mobile internet demand.
In their previous experience with large sporting events like the Superbowl, Cisco noted that the volume of traffic leaving the stadium was greater than the volume entering – all thanks to social media services such as Facebook, YouTube, etc. with people sharing content, something that Intel’s Steve Price raised later on.
Mark suggested that the move to small cells will require a change in mindset, and put forward a suggestion for using converged Wi-Fi/femto architectures for macro offload of indoor traffic – and he also noted that cellular small cells would need to prove themselves at the high densities already deployed with WiFi.


Ubiquisys’ CTO and Founder Will Franks, with a presentation on the next generation of small cells.

Will started things off with a brief discussion on the evolution and naming of small cells, describing how things have progressed from early residential femtos, all the way to some of the especially advanced outdoor and rural models.
The building blocks for the next generation of intelligent small cells, Will stated, are 3G, LTE and Wi-Fi. This, combined with the continuous adaptive behaviour offered by our self-organising network technology, helps Ubiquisys small cells to form part of the recently discussed ‘Edge Cloud’ – something also raised in Intel’s presentation.
Will went on to describe how small cell hotpots will be deployed in the real world, and broke down small cell technology into layers. Starting with the hardware platform (featuring Texas Instruments’ simultaneous dual-mode 3G/LTE), through continuous self organization and self organizing networks, and on to edge cloud computing platforms (Intel) and cloud control systems.
Ubiquisys reported that Softbank Japan have been able to deploy rural femtocells in just 3 days using satellite backhaul. Their "self optimising femto grid" even works for clusters of rural femtocells at 2km range.



Competitive operator Network Norway, thinks it has the answer for small businesses in Norway.
Combine mobile centrex with femtocells. Norway is a country that was at the leading edge of fixed-mobile substitution.
According to Network Norway, 64% of all calls originate on a mobile and 79% of call minutes terminate on a mobile. This is a very mobile friendly country and, believed Network Norway, businesses would be very receptive to mobile centrex.
The problem is buildings: all that concrete, glass and basements make ditching the desk phone an impossibility unless you can bring the mobile network indoors. DAS (distributed antennae systems) are too expensive for most small businesses. Femtocells are not.
Network Norway launched a small business femtocells to make their Mobile Centrex service more compelling. The mobile PaBX service offers hunt groups, stats on attendant function, private number plans, conferencing etc.
What is interesting to me is that they have built smartphone apps (for Ovi, iPhone and Android) which allows users to set up conferences and see presence/availability in contacts (which comes from femtocells).
In other nomenclature, this is called “collaboration”. Or even unified communications, if you use the IM, email and SMS functions on your smart phone.
So benefits for small businesses: flexible communications, collaboration, guaranteed coverage in the office, seamless experience, no capex.


The last presentation day 2 featured Steve Price of Intel, with a look at how to ‘differentiate the small cell user experience with an intelligent, application enabling architecture’.


The internet and mobile internet are both growing rapidly, with the “Gigabit Generation” particular fixated on social networking, which now has a considerable impact on network traffic at large. Service providers are now presented with a great opportunity, Steve said, as they can now take advantage of the fact that they are directly involved in the process.
The next step is to make sure that intelligence is present throughout the network – and just as important is its location. These intelligent services ensure that the user will be getting a better experience in the end.
The two key trends identified by Intel were cloud RAN, with China Mobile named as an example, and edge cloud, where the Intel-Ubiquisys collaboration was given as a prime example.



Individual Contribution: Tom Lismer
Residential Femtocell Access Point Design and Technology Innovation: Picochip
Non-residential femtocell access point design and technology innovation: Alcatel-Lucent
Femtocell Network element design and technology innovation: ip.access
Femtocell Application: New service or technology: Alcatel-Lucent
Progress in commercial deployment: Huawei
Commercial deployment – Marketing Campaign: Vodafone
Commercial Deployment – technical implementation: Vodafone
Contribution to Femtocell Standards: Nokia Siemens Networks
Enabling Technology: Texas Instrument
Social Vision: NEC
Judges Choice: Rakon

Complete Details on Femto Forum Website here.


DAY 3

Surprisingly there wasnt much coverage from Day 3. My observation is that by the third day, the people get really tired and its just the analysts who are still around learning, discussing and participating as much as they can. The only summary I found is from the Think Femtocell blog. Here are few interesting points:

The femto vendor community seems to be frustrated by the slow rollout of Femtos by the network. The technology has been proven and from what I see, if a network is rolling out Femtos, they are getting good reviews and reception from the user community, even though they may have to shell out a few bucks.

Verizon reported tremendous success when using their femtocell (the Verizon Wireless Extender) to reduce churn. They've also successfully offloaded heavy users from their macro network in Chicago, by sending them a free femtocell – both improving speeds for those high users as well as releasing capacity on the macro network for others to benefit from. Their femtocell solution works well and they're very happy with it. You still can't buy a femtocell in a Verizon store because It doesn't fit with their corporate branding of having the best network.

In contrast, Vodafone don't seem to have suffered any loss of brand image by promoting Sure Signal – their network brand remains strong and is arguably strengthened by saying they are the only one who can truly guarantee full service indoors anywhere (assuming there is a DSL line to connect with). Vodafone Ireland jokingly apologised for the lower approval figure than Vodafone Greece during their femtocell trials - only 96% (against 98% in Greece) would recommend them to their friends and family. They explained how they had carefully crafted their marketing message to celebrate the positive aspects of their customer's individual homes (thick woods, stone buildings, basement flats etc.) and how simple it was for them to have 5 bar coverage.

Comcast have built out a lot of Wi-Fi hotspot capacity in addition to their wireline/cable services. They believe in the long term, the usage mix of traffic on wireless will be a similar profile to wireline today – say 50% entertainment (including video), 20% web surfing; a total of 13GB/month. Comcast has deployed some 5000 WiFi hotspots so far, and plan to build out 100K over the coming years.

Wi-Fi has some new features coming – the new HotSpot 2.0, which Comcast will be trialling later this year. Greater use of the 5GHz spectrum will help reduce congestion in high traffic areas. Sports stadiums seem to be the biggest challenge – many users wanting to watch video at the same time, with others trying to use Mi-Fi (cellular to Wi-Fi adaptors) at the same time/in the same spectrum.

Contela explained how they use femtocells in Korea to offload data traffic. Unusually, the system deals with voice and data traffic differently – switching voice calls to the normal macro network while handling as much data traffic as possible through femtocells and Wi-Fi.

TOT, Thailand, a relatively new entrant to mobile explained how they can install femtocells at public payphone booths as a quick way to find sites with backhaul connectivity (using DSL) and power. Getting the height of the unit is important – it needs to be slightly out of reach. They also showed their disaster recovery solution – which uses femtocells + satellite backhaul and can be rapidly deployed. In these situations, providing a fixed/wireline phone service isn't useful – most people now have all their phone numbers held in their mobile phone and not written down. Mesh backhaul, linking clusters of femtocells to each other using wireless and aggregating the backhaul to a few egress points, is also a useful option – a maximum of 5 "hops" using a so-called spine and rib architecture matches urban street layouts.

Stuart Carlaw from ABI Research. Growing number of employees have more than one phone they use in the office (one corporate + one personal). Both phones have mixed voice/data use. After some retrenchment in 2009, voice has continued to grow and is now 779 minutes average for corporate users. Video and picture messaging are being used by enterprise users (on their corporate liable phone) more than ever before. The growing demands of employees are giving their IT departments a major headache, for which enterprise femtocells will be a major part of the solution.

The Femtocell Application developers toolkit from Alcatel-Lucent isn't locked into their solution. Applications developed and tested using their SDK should also work with any other femtocell system that also conforms to the Femtocell Application API.

There were a number of operators present at the conference who are clearly there in an active capacity. Most were pretty tight lipped about their plans, but all seem to acknowledge that femtocells will play some part in the story.


Some Final thoughts from the Ubiquisys Blog.

The latest Informa femtocell market status report, produced for the Femto Forum this week, confirms the strong growth trend with nine new commercial launches in the past quarter alone.

Both operators and vendors alike were talking about femto technology being used in public-space small-cell hotspots to provide a capacity boost in high demand areas. At least half of the presentations touched on this topic in one way or another. Is it because the growth in data demand is beginning to be felt? Or is it that the low opex and backhaul costs of femto are making a strong business case? In any case, many of the questions about public space small cells were mentioned, such as interoperability with the macro layer and how the necessary high density deployment of small cells will be achieved. The questions were mentioned, but solutions were not – a sure sign of innovative work in progress.

Colt Telecom unveiled femtocell infrastructure as a service. Because many operators want to make their first femto launch into a low-risk segment, they often opt for SME (small business) rather than consumer segments. Yet the lower volumes in SME can damage the business case, because the upfront costs of the core gateway and systems integration are shared between fewer customers. By offering an incremental managed service cost, fixed line provider Colt might just have made it easier for mobile operators to start femto services.

Broadcom unveiled a fully integrated femto residential gateway, Texas Instruments won an award for their powerful new 3G/LTE SoC, and Intel presented a future powered by compute platforms in both cloud RAN and edge cloud environments.

There was a degree of consensus that LTE will be seen first in small cell hotspots, the same hotspots that need to deal with a deluge of 3G data demand over the next few years. Several speakers mentioned that this calls for small cells that can run 3G and LTE simultaneously, like those new SoCs from TI.

A few years ago you would have seen quite a few femto vs. Wi-Fi presentations, but no more, which is quite a relief to us, as we have been behind combined femto-Wi-Fi devices since 2008. There was much discussion of harmonisation in home and business environments. In public spaces, the idea of tri-mode small cells replacing Wi-Fi hotspots was raised. These would maintain the Wi-Fi capability, but add 3G and LTE cellular, opening the possibility of using cellular’s invisible “login” to replace Wi-Fi’s usual usernames and passwords.


Sources:

Pics Source - Ubiquisys Blog

Report compiled from:

Monday, 13 June 2011

Home eNode B (HeNB) Architecture options

I blogged last year about the different LTE Home eNodeB architecture options, their advantages and disadvantages. Then there was the Qualcomm white paper architecture that listed these options as well. Now there is a white paper from the Femto Forum that discusses these architecture options in detail and their advantages and disadvantages. The presentation is embedded below.

Friday, 3 June 2011

Carrier Aggregation with a difference

Click on picture to enlarge

Another one from the LTE World Summit. This is from a presentation by Ariela Zeira of Interdigital.

What is being proposed is that Carrier Aggregation can use both the licensed as well as unlicensed bands but the signalling should only happen in the licensed band to keep the operator in control.

Note that this is only proposed for Small Cells / Femtocells.

The only concern that I have with this approach is that this may cause interference with the other devices using the same band (especially ISM band). So the WiFi may not work while the LTE device is aggregating this ISM band and the same goes for bluetooth.

Comments welcome!

Thursday, 17 February 2011

Thursday, 27 January 2011

Attocell: Smaller Femtocell

Over the last year Femtocells et al. have been slowly rebranded as Small cells and I agree that it is a much more generic term and easier for end users to understand.

Last year, around this time, magicJack announced a small USB Femtocell (a lot of Femto manufacturers disagree that its a Femtocell) that can help reduce the cost of call and just a few days back Picochip announced picoXcell, a USB form factor femtocell.

Yesterday, Ubiquisys announced the Attocell. As can be seen in the picture above, in mathematics, femto is 10^-15 and atto is 10^-18. I know that some of you may think that there is still scope for zeptocells and yoctocells but it may be difficult to see in the light of Attocells, what they can be.

A few years back, I blogged about how Femtocells can be used to steal the spectrum. Well, Attocell legally allows to do just that. The press release states the following:

The attocell connects to a user’s laptop via USB, which provides power and an internet connection. It then analyses the IP address and radio environment to determine which country it is in, and sets its 3G radio power accordingly to below the licenced level. In some countries its range will be just 5mm, in other countries, it could cover a whole room.

Like Ubiquisys femtocells, the attocell continuously monitors its radio environment to ensure that there is zero impact on existing mobile networks. This intelligence, combined with its tiny power output, is likely to make the attocell exempt from regulatory controls and the requirement for type approval.

In 5mm mode, the traveller simply lays the iPhone on top of the device and the phone connects automatically, just like a regular femtocell. Calls can be made using a Bluetooth or wired headset , or by using the iPhone’s speaker.

You can understand more by reading the official Attocell FAQ here.

It would be very interesting to see if any of the big operators support this device. Roaming revenues are big part of operators profit. Informa has predicted that this roaming revenue will keep rising. The roaming revenue comes from voice, sms as well as data. Some business users in one business trip frequently shell as much as a personal user would for a years contract. So its not really in operators interest to promote these devices.

On the other hand, small operators and MVNO may really like this as this can help them win more subscribers and can be the differentiators in the market.

Once more thing worth remembering is that since the arrival of Skype, the occasional and cautious mobile users have no hesitation on making VoIP calls and keeping friends, family and colleagues back home up to date with their status. The operators are aware of this and wouldnt mind the users instead using their mobiles via attocell.

Ubiquisys will show the Attocell in MWC in mid-Feb and we will have to wait and see the reaction.

Saturday, 22 January 2011

Wilson Street: What can femtocells do - the next big thing!

I have blogged about the Alcatel-Lucent (ALU) Femtocells in the past. Few months back I posted about their shift from using the term Femtocells to Small cells. To make everyone aware of this small cells they launched their Wilson Street experiment and are now producing some episodes to show how these small cells can play big part in everyday life.

The first two episodes are embedded below from Youtube.






The latest (3rd) episode is available on the Wilson Street Website here.

Tuesday, 14 December 2010

What are Heterogeneous Networks (HetNets)?

HetNets are hot. I hear about them in various contexts. Its difficult to find exactly what they are and how they will work though. There is a HetNets special issue in IEEE Communications Magazine coming out next year but that's far away.

I found an interesting summary on HetNets in Motorola Ezine that is reproduced below:


“The bigger the cell site, the less capacity per person you have,” said Peter Jarich, research director with market intelligence firm Current Analysis. “If you shrink coverage to a couple of blocks, you are having that capacity shared with a fewer number of people, resulting in higher capacity and faster data speeds.”

This is a topic the international standards body, the Third Generation Partnership Project (3GPP), has been focusing on to make small cells part of the overall cellular network architecture.

“What we’re seeing is a natural progression of how the industry is going to be addressing some of these capacity concerns,” said Joe Pedziwiatr, network systems architect with Motorola. “There is a need to address the next step of capacity and coverage by introducing and embracing the concepts of small cells and even looking at further advances such as better use of the spectrum itself.”

As such, discussion regarding this small-cell concept has emerged into what is called heterogeneous networks, or Het-Net, for short. The idea is to have a macro wireless network cooperating with intelligent pico cells deployed by operators to work together within the macro network and significantly improve coverage and augment overall network capacity. Small cells can also be leveraged to improve coverage and deliver capacity inside buildings. Indoor coverage has long been the bane of mobile operators. Some mobile operators are already leveraging this concept, augmenting their cellular service offering with WiFi access to their subscriber base in order to address the in-building coverage and capacity challenges facing today’s cellular solutions.

Pedziwiatr said this Het-Net structure goes far beyond what is envisioned for femtocells or standard pico cells for that matter. Introducing a pico cell into the macro network will address but just one aspect of network congestion, namely air interface congestion. The backhaul transport network may become the next bottleneck. Finally, if all this traffic hits the core network, the congestion will just have shifted from the edge to the core.

“This requires a system focus across all aspects of planning and engineering,” Pedziwiatr said. “We’re trying to say it goes beyond that of a femto. If someone shows up at an operator and presents a pico cell, that is just one percent of what would be needed to provide true capacity relief for the macro network.”

Femtocells, otherwise known as miniature take-home base stations, are obtained by end users and plugged into a home or office broadband connection to boost network signals inside buildings. A handful of 3G operators worldwide are selling femtocells as a network coverage play. For the LTE market, the Femtocell Forum is working to convince operators of the value of a femtocell when it comes to better signal penetration inside buildings and delivering high-bandwidth services without loading the mobile network. This is possible, because the backhaul traffic runs over the fixed line connection. However, this femtocell proposition largely relies on end user uptake of them—not necessarily where operators need them, unless they install femtocells themselves or give end users incentives to acquire them.

As with any new concept, there are challenges to overcome before Het-Nets can become reality. Het-Nets must come to market with a total cost of ownership that is competitive for an operator to realize the benefit of providing better capacity, higher data speeds, and most of all, a better end-user experience said Chevli.

“The level of total cost of ownership has to be reduced. That is where the challenge is for vendors to ensure that any new solution revalidates every existing tenet of cellular topology and evolve it to the new paradigm being proposed,” Chevli said. “You can’t increase the number of end nodes by 25X and expect to operate or manage this new network with legacy O&M paradigms and a legacy backhaul approach.”

One of the issues is dealing with interference and Het-Net network traffic policies. “How do you manage all of these small cell networks within the macrocell network?” asked Jarich. “Right now if you have a bunch of femtocells inside a house, there is this concept that the walls stop the macrocell signals from getting in and out. You get a separation between the two. Go outdoors with small cells underlying bigger cells and you get a lot more interference and hand-off issues because devices will switch back and forth based on where the stronger signal is.”

Pedziwiatr said for a Het-Net to work, it would require a change in node management, whereby an operator isn’t burdened with managing big clusters of small cells on an individual basis. “We see elements of SON (self organizing networks), self discovery and auto optimization that will have to be key ingredients in these networks. Otherwise operators can’t manage them and the business case will be a lot less attractive,” he said.

Fortunately, the industry has already been working with and implementing concepts of SON in LTE network solutions. In the femtocell arena also, vendors have been incorporating some elements and concepts of SON so that installing them is a plug-and-play action that automatically configures the device and avoids interference. But even then, Het-Nets will require further SON enhancement to deal with new use cases, such as overlay (macro deployment) to underlay (pico deployments) mobility optimization.

When it comes to LTE, SON features are built into the standard, and are designed to offer the dual benefit of reducing operating costs while optimizing performance. SONs will do this by automating many of the manual processes used when deploying a network to reduce costs and help operators commercialize their new services faster. SON will also automate many routine, repetitive tasks involved in day-to-day network operations and management such as neighbor list discovery and management.

Other key sticking points are deployment and backhaul costs. If operators are to deploy many small cells in a given area, deploying them and backhauling their traffic should not become monumental tasks.

Chevli and Pedziwiatr envision Het-Nets being deployed initially in hot zone areas – where data traffic is the highest – using street-level plug-and-play nodes that can be easily installed by people with little technical know-how.

“Today, macro site selection, engineering, propagation analysis, rollout and optimization are long and expensive processes, which must change so that installers keep inventories of these units in their trucks, making rollout simple installations and power-ups,” said Pedziwiatr. “These will be maintained at a minimum with quick optimization.”

The notion of backhauling traffic coming from a large cluster of Het-Net nodes could also stymie Het-Nets altogether. Chevli said that in order to keep costs down, Het-Net backhaul needs to be a mix of cost-effective wireless or wired backhaul technology to aggregate traffic from what likely will be nodes sitting on lamp posts, walls, in-building and other similar structures. The goal then is to find a backhaul point of presence to aggregate the traffic and then put that traffic on an open transport network in the area.

Backhaul cost reductions may also be a matter of finding ways to reduce the amount of backhaul forwarded to the core network, Pedziwiatr said. These types of solutions are already being developed in the 3G world to cope with the massive data traffic that is beginning to crush networks. For traffic such as Internet traffic, which doesn’t need to travel through an operator’s core network, offloading that traffic as close to the source as possible would further drive down the cost of operation through the reduction of backhaul and capacity needs of the core network.

In the end, with operators incorporating smaller cells as an underlay to their macro network layer rather than relying on data offloading techniques such as femtocells and WiFi that largely depend on the actions of subscribers and impacted by the surrounding cell operating in the same unlicensed frequency, Het-Nets in licensed spectrum will soon become the keystone in attacking the ever-present congestion issue that widely plagues big cities and this is only likely to get worse over time.

Image Source: Dr. Daichi Imamura, Panasonic presentation.