Sunday 23 October 2011

Femtocells for Low Energy Buildings

Exactly three years back I posted an article about 'Femtocells for Radiation Proofed Homes' and when I saw this presentation by Elisa, Finland, It just validated with the research what I had mentioned. With the government push for more low energy infrastructure and at the same time the new technologies using higher frequencies, this problem is going to keep getting worse. Untill ofcourse the coming of 'Wireless Friendly Buildings'.

Elisa's presentation as follows:

Saturday 22 October 2011

Ericsson Video: Using LTE to broadcast Danish elections



Danes elected a new parliament September 15. As four teams from TV 2 moved between party headquarters, Parliament House and celebration sites, they used standard off-the-shelf LTE terminals to upload interviews to the tv-station, which in turn broadcast the content live to viewers on their channel.

The solution is provided by operator TDC, on the network supplied and managed by Ericsson.

Friday 21 October 2011

'Internet Trends' and 'Mobile Internet Trends' by Mary Meeker

Came across this article from InformationWeek based on this presentation by Mary Meeker. Few points to note from the article:

Mobile: Mobile subscriber growth is continuing at a pace that matches the meteoric rise of Internet adoption, a rate that puts other technologies like TV to shame. Meeker cited 35% year-on-year mobile 3G subscriber growth and noted that smartphone shipments have surpassed feature phone shipments in the U.S. and Europe. She also highlighted the explosive growth of iPhone, iPad, and (particularly) Android.

User Interface: Interface matters. "Before Steve Jobs, computers were utilitarian tools for computation," said Meeker. "After Steve, computers became beautiful objects we could use in thousands of ways to aim to make life better." In the wake of the iPhone and the iPad, there's a revolution in the way we interact with computers, through touch and voice, while mobile. "We think the next big things are the things on the sides of your head," said Meeker. "Those would be your ears." She was referring to the innovation seen in voice recognition, sound creation and sharing, and audio interfaces like headphones recently.

America Leads In Mobile Innovation: Despite the general economic doldrums in the U.S., American companies are leading the way toward the mobile era. Made-in-the-USA smartphone operating systems--Android, iOS, and Windows Mobile--have gone from 5% market share in 2005 to 65% today. "The pace of innovation in Silicon Valley may be unprecedented," said Meeker.

Mobile Devices Are Empowering People: Some 85% of people in the world have access to the wireless grid, more than have access to electricity. Over 200 million farmers in India receive payments via mobile devices. Meeker pointed out how instrumental such devices have been during disasters like the March earthquake and tsunami in Japan. "When people look back at this era that we're living in now, they'll say this was the time people got empowered by mobile devices," said Meeker.

The video of her talk is embedded below:



Couple of presentations from her are embedded below:





Tuesday 18 October 2011

HD Voice - Next step in the evolution of voice communication

Nearly 2 years back I blogged about Orange launching HD Voice via the use of AMR-WB (wideband) codecs. HD voice is already fully developed and standardized technology and has so far been deployed on 32 networks in almost as many countries.

People who have experienced HD voice say it feels like they are talking to a person in the same room. Operators derive 70 percent of their revenue from voice and voice-related services, and studies show that subscribers appreciate the personal nature of voice communication, saying it offers a familiar and emotional connection to another person.

HD voice is also a reaction to the competition faced by the operators from OTT players like Skype.

Below is an embed from the recent whitepaper by Ericsson:



For more information also see:



Friday 14 October 2011

Gartner Hype Cycle - Internet of Things


Click on the picture to enlarge

Interesting pic showing the Hype Cycle for different technologies. I picked it up from this interesting presentation on Internet Of Things here.

Monday 10 October 2011

What is GELTE?

GSM, EDGE and LTE Interworking.
This presentation available to download from here.

Wednesday 5 October 2011

Simultaneous Voice and LTE (SVLTE)


When LTE is an overlay to a CDMA/EV-DO network, the current de facto standard for voice delivery is Simultaneous Voice and LTE (SVLTE). In this arrangement, voice service is deployed as a 1x service running in parallel with LTE data services. For this solution to work, the handset needs to have two radios that are on simultaneously. The problem that is obvious is that the power consumption would generally be higher as two radios are on when the voice call is ongoing. The advantage (and I think its a big advantage) is that the data speeds are not affected by ongoing voice call and at the same time the state machine is simple.

For some reason this idea is not very popular for the 2G/3G evolution to LTE as the reliance will be on the CS Fallback. I had discussed this idea in the LTE World Summit and had blogged about it, you can read more details and comments here.

There is also a recent whitepaper from Huawei that covers these issues going towards VoLTE. Its available here.

Edit 06/10/11: Changed the acronym of SVLTE from 'Simultaneous Voice Over LTE' to 'Simultaneous Voice and LTE' as this is correct and referred to elsewhere.

Monday 3 October 2011

LTE Survey from Telecom Asia and Maravedis

Click on the pic. to enlarge

Interesting survey results. As seen in Fig. 2 above if Video and P2P is the main drivers for LTE for some operators, soon they may end up in trouble as the users will consume as much as allowed and given opportunity. An interesting thing though is that the operators are thinking of a fallback strategy that includes Wifi, Femtocells and Picocells (Fig. 3). Finally (Fig. 4), interesting to see that operators believe in launching Smartphones for LTE, I guess CS Fallback is the only possible option for the time being (and maybe for some time to come).

You can read the complete report below:
If its too difficult to read the embed, go to Slideshare here and download presentation.

Saturday 1 October 2011

Future Mobile devices: Winners & Losers in technology

NTT DOCOMO announced a range of futuristic ideas and products that they are going to demo at CEATEC this month. Some of the products/ideas as follows:

Extra-high-speed, next-generation LTE service

  • Experience the first Xi-compatible tablets “docomo Tablet GALAXY Tab 10.1 LTE SC-01D” and “docomo Tablet ARROWS Tab LTE F-01D,” set for October release.
  • Try out new broadband services for the high-performance Xi network, including internationally popular services and games such as Hulu and Qik Video.

Smartphone-ready device to measure acetone in breath for diet support

  • The compact device measuring acetone for diet support that can easily be used anywhere and anytime.
  • Visitors blow into the smartphone-connected device to measure acetone in their breath-the higher the concentration, the greater the level of hunger.
  • The device also identifies when people are burning fat, based on the concentration of acetone in their breath, which rises when body fat is being burnt.

Smartphone jacket for ultra-high-speed battery charging

  • This special battery jacket for smartphones achieves a full charge in just 10 minutes. A recharging indicator will show how the jacket will charge a smartphone 10~15 times faster than conventional charging devices.

Smartphone jackets for various purposes

  • Three types of special jackets for smartphones that are equipped with sensors that can be customized to measure ultraviolet light and bad breath, gamma radiation and body fat.

Environmental sensor network

  • Presentation of real-time atmospheric data (temperature, humidity, wind direction/speed, precipitation, ultraviolet intensity) collected by DOCOMO’s nationwide network of approximately 2,500 environmental sensors, and a demonstration of visualizing the data using augmented reality.

The DOCOMO booth will also offer a mobile handset recycling service, where visitors can drop off old and unwanted mobile phones, rechargers, battery packs and stands. This service is open to all mobile phone users regardless of their carrier, and mobile phones will be destroyed using specialized tools to ensure the protection of personal information.

You can watch these in action here:








I also recently attended a Cambridge Wireless Handset SIG event and David Wood gave an interesting presentation that is embedded below:

Other presentations from that event available here.

Friday 30 September 2011

Macrocells or Metrocells?

Just went through Alcatel-Lucent strategic paper on whether to go for more Macrocell sites or rather have Metrocells instead.

A good description of Metrocells is available in the document:

Metro cells, the latest evolution in small cells, are based on the same low cost femtocell technology that has been successfully used in home and enterprise cells, but with enhanced capacity and coverage. With higher processing and transmit power, the first generation of metro cells is engineered to serve from 16 to 32 users and provide a coverage range from less than 100 meters in dense urban locations to several hundred meters in rural environments. However, unlike home and enterprise cells, metro cells are owned and managed by a MSP and typically used in public or open access areas to augment the capacity or coverage of a larger macro network.

Available in both indoor and outdoor versions, metro cells are plug-and-play devices that use Self-Organizing Network (SON) technology to automate network configuration and optimization, significantly reducing network planning, deployment and maintenance costs. While indoor versions use an existing broadband connection to backhaul traffic to a core network, outdoor versions may be opportunistically deployed to take advantage of existing wireline or wireless sites and backhaul infrastructure, such as Fiber-to-the-Node (FTTN), Fiber-to-the-Home (FTTH), Very-high-speed Digital Subscriber Line (VDSL) street cabinets, and DSL backbone.

Since metro cells use licensed spectrum and are part of the MSP’s larger mobility network, they provide the same trusted security and quality of service (QoS) as the macro network. With seamless handovers, users can roam from metro cells to the macro network and vice versa. Metro cells also deliver the same services as the macro network (for example, voice, Short Message Service (SMS), and multimedia services), and support application programming interfaces (APIs), that may be used for developing new, innovative services. In short, metro cells promise to be the ideal small cells for network offloading.

For more details on the whitepaper see: http://www.slideshare.net/zahidtg/metro-cells-whitepaper



Saturday 24 September 2011

Public training on UMTS and HSPA/HSPA+


We are conducting our first public training on UMTS and HSPA/HSPA+. There are still a lot of people working on UMTS / HSPA / HSPA+ even though quite a lot of focus is being put on LTE.

This course is split into 3 parts and the person attending it can decide which days he wants to attend. The intention is to bring a person with minimal knowledge upto a good speed and to a level where (s)he can become an expert by putting some extra effort.


Discounts available for regular readers of this blog. Please ask.

Tuesday 20 September 2011

Panel Session on Small Cells (Femtocells) from Cambridge Wireless SIG event

Panel Session on Small Cells (Femtocells) from Cambridge Wireless SIG event from Zahid Ghadialy on Vimeo.

From the Cambridge Wireless Small Cell Special Interest Group event


“Small Cells: the beginning and where we are now”

15 September 2011

At The IET, Savoy Place, London, WC2R 0BL


Panel Session

Chair: Mike Bowerman, Account Manager, Alcatel Lucent.

Participants (from Left to right):

Professor Will Stewart, IET

Houston Spencer, VP Solutions and Marketing, Alcatel-Lucent

Will Franks, CTO and Founder, Ubiquisys

Chris Cox, Director of Marketing, ip.access

More details about the speakers and the event available at: http://www.cambridgewireless.co.uk/Agenda/SCS1_15.09.11.pdf


Monday 19 September 2011

Summary from the 'Small Cells' Event in Cambridge Wireless

We recently had our first 'Small Cells' SIG event in Cambridge Wireless entitled 'Small Cells: The beginning and where we are now'. The following presentation is the Introduction to Cambridge wireless and the 'Small Cells' SIG (special interest group).


Embedded below are the slides and the videos that were taken by our host for the day, 'The IET'.

The first presentation was by Prof. Will Stewart of The IET entitled 'Small Cells - Why small cells?'.



Next presentation: 'Small Cells - the big brother of femtocells. Why they are needed, and where is the femtocell market that they build on' by Will Franks, Ubiquisys



Next Presentation: 'Small Cells - On the origin of Small Cells by means of natural selection, or the preservation of favoured providers in the struggle for mobile broadband' by Houston Spencer, Alcatel-Lucent



Final Presentation: 'Small Cells - Mass scale femtocell deployments' by Chris Cox, IP.Access



Overall it was a good event. The main complaint was that people had lots of questions but didnt get to ask them. Hopefully they will ask them in the future events.

Wednesday 14 September 2011

Inter-technology Carrier Aggregation

Another one from the 4G Americas whitepaper of Mobile Broadband explosion:

Carrier aggregation will play an important role in providing operators maximum flexibility for using all of their available spectrum. By combining spectrum blocks, LTE-Advanced will be able to deliver much higher throughputs than otherwise possible. Asymmetric aggregation (i.e., different amounts of spectrum used on the downlink versus the uplink) provides further flexibility and addresses the fact that currently there is greater demand on downlink traffic than uplink traffic. Specific types of aggregation include:

  • Intra-band on adjacent channels.
  • Intra-band on non-adjacent channels.
  • Inter-band (e.g., 700 MHz, 1.9 GHz).
  • Inter-technology (e.g., LTE on one channel, HSPA+ on another). This is currently a study item for Release 11. While theoretically promising, a considerable number of technical issues will have to be addressed.

Tuesday 13 September 2011

CELL_FACH to LTE Mobility

At the moment, transition from RRC states from UMTS to LTE can happen from CELL_DCH to E-UTRA_RRC_CONNECTED state via Handover or from UTRA_IDLE to E-UTRA_RRC_IDLE via Cell Reselection. There is a study ongoing to transition from CELL_FACH to LTE. The state has not been specified but my guess is that it would probably be E-UTRA_RRC_CONNECTED. The following is the reasoning based on RP-111208:

It is our understanding that some of the Cell_FACH enhancement proposals for Release 11 are targeted to make it more attractive to keep UEs longer in the Cell_FACH state than is expected with pre-Rel-11 devices. This expectation that the UEs may stay longer in the Cell_FACH state is in turn motivating the mobility from Cell_FACH state to LTE proposal.

For instance, as the network can already today release the Cell_FACH UE’s RRC Connection with redirection, network may want to redirect UE to the correct RAT and frequency based on the UE measurement. Specifically if the network strategy is to keep the UEs long time in Cell_FACH state, it would make sense to provide the network the tools to manage the UEs’ mobility in that state. In addition, the needs for mobility to LTE are somewhat different from mobility to e.g. GERAN, as the former would be typically priority based while the latter would happen for coverage reasons. Thus, if introduced, the network controlled mobility from UMTS Cell_FACH would be specifically interesting for the UMTS to LTE case.


Will update once I have more info.

Monday 12 September 2011

LTE Rollouts and Deployment Scenarios

According to GSA report, as of August 2011, 26 commercial LTE networks in 18 countries are already rolled out as below:
As of Aug. 2011, 237 operators in 85 countries are investing in LTE:

* 174 LTE network commitments in 64 countries
* 63 pre-commitment trials in 21 more countries
* 26 commercial LTE networks launched
* At least 93 LTE networks are expected to be in commercial service by end 2012

The following is from the 4G Americas whitepaper:

There are many different scenarios that operators will use to migrate from their current networks to future technologies such as LTE. Figure 10 presents various scenarios including operators who today are using CDMA2000, UMTS, GSM and WiMAX. For example, as shown in the first bar, a CMDA2000 operator in scenario A could defer LTE deployment to the longer term. In scenario B, in the medium term, the operator could deploy a combination of 1xRTT, EV-DO Rev A/B and LTE and, in the long term, could migrate EV-DO data traffic to LTE. In scenario C, a CDMA2000 operator with just 1xRTT could introduce LTE as a broadband service and, in the long term, could migrate 1xRTT users to LTE including voice service.


3GPP and 3GPP2 both have specified detailed migration options for current 3G systems (UMTS-HSPA and EV-DO) to LTE. Due to economies of scale for infrastructure and devices, 3GPP operators are likely to have a competitive cost advantage over Third Generation Partnership Project 2 (3GPP2) operators. One option for GSM operators that have not yet committed to UMTS, and do not have an immediate pressing need to do so, is to migrate directly from GSM/EDGE or Evolved EDGE to LTE with networks and devices supporting dual-mode GSM-EDGE/LTE operation.

Saturday 10 September 2011

Wednesday 7 September 2011

Enhanced Voice Service (EVS) Codec for LTE Rel-10

Its been a while we talked about codecs.


The traditional (narrowband) AMR (Adaptive Multi-Rate) codec operates on narrowband 200-3400 Hz signals at variable bit rates in the range of 4.75 to 12.2 kbps. It provides toll quality speech starting at 7.4 kbps, with near-toll quality and better robustness at lower rates and better reproduction of non-speech sounds at higher rates. The AMR-WB (Wideband) codec provides improved speech quality due to a wider speech bandwidth of 50–7000 Hz compared to narrowband speech coders which in general are optimized for POTS wireline quality of 300–3400 Hz. Couple of years back Orange was in news because they were the first to launch phones that support HD-Voice (AMR-WB).

Extended Adaptive Multi-Rate – Wideband (AMR-WB+) is an audio codec that extends AMR-WB. It adds support for stereo signals and higher sampling rates. Another main improvement is the use of transform coding (transform coded excitation - TCX) additionally to ACELP. This greatly improves the generic audio coding. Automatic switching between transform coding and ACELP provides both good speech and audio quality with moderate bit rates.

As AMR-WB operates at internal sampling rate 12.8 kHz, AMR-WB+ also supports various internal sampling frequencies ranges from 12.8 kHz to 38.4 kHz. AMR-WB uses 16 kHz sampling frequency with a resolution of 14 bits left justified in a 16-bit word. AMR-WB+ uses 16/24/32/48 kHz sampling frequencies with a resolution of 16 bits in a 16-bit word.


Introduction of LTE (Long Term Evolution) brings enhanced quality for 3GPP multimedia services. The high throughput and low latency of LTE enable higher quality media coding than what is possible in UMTS. LTE-specific codecs have not yet been defined but work on them is ongoing in 3GPP. The LTE codecs are expected to improve the basic signal quality, but also to offer new capabilities such as extended audio bandwidth, stereo and multi-channels for voice and higher temporal and spatial resolutions for video. Due to the wide range of functionalities in media coding, LTE gives more flexibility for service provision to cope with heterogeneous terminal capabilities and transmission over heterogeneous network conditions. By adjusting the bit-rate, the computational complexity, and the spatial and temporal resolution of audio and video, transport and rendering can be optimised throughout the media path hence guaranteeing the best possible quality of service.

A feasibility study on Enhanced Voice Service (EVS) for LTE has recently been finalised in 3GPP with the results given in Technical Report 22.813 ‘‘Study of Use Cases and Requirements for Enhanced Voice Codecs in the Evolved Packet System (EPS)”. EVS is intended to provide substantially enhanced voice quality for conversational use, i.e. telephony. Improved transmission efficiency and optimised behaviour in IP environments are further targets. EVS also has potential for quality enhancement for non-voice signals such as music. The EVS study, conducted jointly by 3GPP SA4 (Codec) and SA1 (Services) working groups, identifies recommendations for key characteristics of EVS (system and service requirements, and high level technical requirements on codecs).

The study further proposes the development and standardization of a new EVS codec for LTE to be started. The codec is targeted to be developed by March 2011, in time for 3GPP Release 10.

Fig. above illustrates the concept of EVS. The EVS codec will not replace the existing 3GPP narrowband and wideband codecs AMR and AMR-WB but will provide a complementing high quality codec via the introduction of higher audio bandwidths, in particular super wideband (SWB: 50–14,000 Hz). It will also support narrowband (NB: 200–3400 Hz) and wideband (WB: 50–7000 Hz) and may support fullband audio (FB: 20–20,000 Hz).

More details available in the following whitepapers by Nokia [PDF]:

Sunday 4 September 2011

HSPA+ Advanced - Enhancements beyond R10

Looks like Qualcomm is becoming my favourite company as the last few blog posts have been based on their documents and presentations. This one is a continuation of the last post on Multipoint HSPA.

Related post: HSPA evolution – beyond 3GPP Release 10 - Ericsson

Friday 2 September 2011

Multipoint HSDPA / HSPA

The following is from 3GPP TR 25.872 - Technical Specification Group Radio Access Network; HSDPA Multipoint Transmission:

HSPA based mobile internet offerings are becoming very popular and data usage is increasing rapidly. Consequently, HSPA has begun to be deployed on more than one transmit antenna or more than one carrier. As an example, the single cell downlink MIMO (MIMO-Physical layer) feature was introduced in Release 7. This feature allowed a NodeB to transmit two transport blocks to a single UE from the same cell on a pair of transmit antennas thus improving data rates at high geometries and providing a beamforming advantage to the UE in low geometry conditions. Subsequently, in Release-8 and Release-9, the dual cell HSDPA (DC-HSDPA) and dual band DC-HSDPA features were introduced. Both these features allow the NodeB to serve one or more users by simultaneous operation of HSDPA on two different carrier frequencies in two geographically overlapping cells, thus improving the user experience across the entire cell coverage area. In Release 10 these concepts were extended so that simultaneous transmissions to a single UE could occur from four cells (4C-HSDPA).

When a UE falls into the softer or soft handover coverage region of two cells on the same carrier frequency, it would be beneficial for the non-serving cell to be able to schedule packets to this UE and thereby improving this particular user’s experience, especially when the non-serving cell is partially loaded. MultiPoint HSDPA allows two cells to transmit packets to the same UE, providing improved user experience and system load balancing. MultiPoint HSDPA can operate on one or two frequencies.

Click to enlarge

There is also an interesting Qualcomm Whitepaper on related topic that is available to view and download here. The following is from that whitepaper:

The simplest form of Multipoint HSPA, Single Frequency Dual Cell HSPA (SFDC-HSPA), can be seen as an extension to the existing DC-HSPA feature. While DC-HSPA allows scheduling of two independent transport blocks to the mobile device (UE) from one sector on two frequency carriers, SFDC-HSPA allows scheduling of two independent transport blocks to the UE from two different sectors on the same carrier. In other words, it allows for a primary and a secondary serving cell to simultaneously send different data to the UE. Therefore, the major difference between SFDC-HSPA and DC-HSPA operation is that the secondary transport block is scheduled to the UE from a different sector on the same frequency as the primary transport block. The UE also needs to have receive diversity (type 3i) to suppress interference from the other cell as it will receive data on the same frequecny from multiple serving cells.Figure 1 llustrates the high-level concept of SFDC-HSPA.

In the case where the two sectors involved in Multipoint HSPA transmission belong to the same NodeB (Intra-NodeB mode), as illustrated in Figure 2, there is only one transmission queue maintained at the NodeB and the RNC. The queue management and RLC layer operation is essentially the same as for DC-HSPA.

In the case where the two sectors belong to different NodeBs (Inter-NodeB mode), as illustrated in Figure 2, there is a separate transmission queue at each NodeB. RLC layer enhancements are needed at the RNC along with enhanced flow control on the Iub interface between RNC and NodeB in order to support Multipoint HSPA operation across NodeBs. These enhancements are discussed in more detail in Section 4. In both modes, combined feedback information (CQI and HARQ-ACK/ NAK) needs to be sent on the uplink for both data streams received from the serving cells. On the uplink, the UE sends CQIs seen on all sectors using the legacy channel structure, with timing aligned to the primary serving cell.

When two carriers are available in the network, there is an additional degree of freedom in the frequency domain. Dual Frequency Dual Cell HSPA (DFDC-HSPA) allows exploiting both frequency and spatial domains by scheduling two independent transport blocks to the UE from two different sectors on two different frequency carriers. For a DC-HSPA capable UE, this is equivalent to having independent serving cells on the two frequency carriers. In Figure 3, UE1 is in DC-HSPA mode, whereas UE2 is in DFDC-HSPA mode.

Dual Frequency Four-Cell HSPA (DF4C-HSPA) can be seen as a natural extension of DFDC-HSPA, suitable for networks with UEs having four receiver chains. DF4C-HSPA allows use of the four receiver chains by scheduling four independent transport blocks to the UE from two different sectors on two different frequency carriers. DF4C-HSPA is illustrated in Figure 4.

Like SFDC-HSPA; DFDC-HSPA and DF4C-HSPA can also be intra-NodeB or inter-NodeB, resulting in an impact on transmission queue management, Iub flow control and the RLC layer.

Advantages of Multipoint transmission:
* Cell Edge Performance Improvement
* Load balancing across sectors and frequency carriers
* Leveraging RRU and distributed NodeB technology

Multipoint HSPA improves the performance of cell edge users and helps balance the load disparity across neighboring cells. It leverages advanced receiver technology already available in mobile devices compatible with Release 8 and beyond to achieve this. The system impact of Multipoint HSPA on the network side is primarily limited to software upgrades affecting the upper layers (RLC and RRC).


Thursday 1 September 2011

Device to Device communication (FlashLinQ?)

Recently I read on twitter that Qualcomm has asked 3GPP to do a study on device to device communication. Sometime back I blogged about FlashLinQ, Qualcomm's proprietary P2P communication technology. I am not sure if Qualcomm is pushing for this one or wants to have a study in general. If you know more details please add as comments.

Meanwhile, I found this video that explains what FlashLinQ does:



And there is also this presentation which is less technical and explains the information in the video.

More technically detailed presentation embedded in my earlier blog post here.

Wednesday 31 August 2011

Ultra Self Organising Networks (UltraSON)

While watching the Femtocell Video, I was a bit curious on what exactly UltraSON does, so I decided trying to find more info. Surprisingly the information was hard to come by. I finally managed to find the Qualcomm site that has more details but surprisingly it wasnt east to find. From the website (link at bottom):

Qualcomm femtocell R&D program is focused on developing self organizing network features to address interference and mobility management for femtocell deployment in residential and enterprise environments. Interference and mobility management is a chief concern especially when operators are planning for high levels of perfromace from dense and an unplanned femtocell deployments. Qualcomm has developed UltraSON™, a comprehensive suite of interference and mobility management techniques for femtocell deployments in residential and enterprises.

The techniques that make UltraSON:


More details on UltraSON at : http://www.qualcomm.com/research/femtocells

Interesting promotional Femtocell video by Qualcomm

Friday 26 August 2011

Two interesting NGMN papers on Backhaul

There are some interesting blog posts on Broadband Traffic Managemenet on Backhaul. Here are few excerpts:

Traditional network management practice says that network element usage level should not exceed 70% of its capacity. If it does - it is time to do something - buy more or manage it better. So, according to a recent Credit Suisse report - it is time to do something for wireless networks, globally. For North America, where current utilization at peak time reaches 80% it is even urgent.

Phil Goldstein (pictured) reports to FierceWireless that - "Wireless networks in the United States are operating at 80 percent of total capacity, the highest of any region in the world, according to a report prepared by investment bank Credit Suisse. The firm argued that wireless carriers likely will need to increase their spending on infrastructure to meet users' growing demands for mobile data .. globally, average peak network utilization rates are at 65 percent, and that peak network utilization levels will reach 70 percent within the next year. .. 23 percent of base stations globally have capacity constraints, or utilization rates of more than 80 to 85 percent in busy hours, up from 20 percent last year .. In the United States, the percentage of base stations with capacity constraints is 38 percent, up from 26 percent in 2010"

And

The Yankee Group provides the following forecast for mobile backhaul:
Average macrocell backhaul requirements were 10 Mbps in 2008 (seven T1s, five E1s). In less than three years, they have more than tripled to 35 Mbps in 2011, and by 2015, Yankee Group predicts they will demand 100 Mbps.
There were 2.4 million macro cell site backhaul connections worldwide in 2010, growing to 3.3 million by [2015?]
Yankee's new research conclude:

"The market for wholesale backhaul services in North America will grow from $2.45 billion in 2010 to $3.9 billion in 2015, with the majority of this growth coming from Ethernet backhaul. Successful backhaul service providers will be those that can demonstrate price/performance and reliability, have software tools in place and can meet the specific needs of the mobile market.

And recently:

A Dell'Oro Group report forecasts that "Mobile Backhaul market revenues are expected to approach $9B by 2015. This updated report tracks two key market segments: Transport, which includes microwave and optical equipment, and Routers and Switches, which includes cell site devices, carrier Ethernet switches, and service provider edge routers .. routers and switches expected to constitute 30% of mobile backhaul market "

Shin Umeda, Vice President of Routers research at Dell’Oro Group said: “Our research has found that operators around the world are concerned with the rate of mobile traffic growth and are transitioning to Internet Protocol (IP) technologies to build a more efficient and scalable backhaul network. Our latest report forecasts the demand for IP-based routers and switches will continue to grow through 2015, almost doubling the market size of the Router and Switches segment in the five-year forecast period”

I have some basic posts on why Backhaul is important, here and here.

NGMN has timely released couple of whitepapers on the Backhaul.

The first one, 'Guidelines for LTE Backhaul Traffic Estimation' document describes how a model is developed to predict traffic levels in transport networks used to backhaul LTE eNodeBs. Backhaul traffic is made up of a number of different components of which user plane data is the largest, comprising around 80-90% of overall traffic, slightly less when IPsec encryption is added. These results reveal that the cell throughput characteristics for data carrying networks are quite different to those of voice carrying networks.

The purpose of second one, 'NGMN Whitepaper LTE Backhauling Deployment Scenarios' is to support operators in their migration from current architectures to new, packet-based backhaul networks. With the introduction of LTE operators need to look at how the backhauling network, the network domain that connects evolved NodeBs (eNBs) to MME and S/P-GW, is capable of adapting to the new requirements, namely the adoption of a packet infrastructure, without disrupting the existing services. This paper introduces some reference architectures, moving from a pure layer 2 topology to a full layer 3 one, discussing some elements to be considered in the design process of a network.

They are both long but interesting read if you like to learn more about Backhaul and the best way in future proofing the network deployments.

Wednesday 24 August 2011

LTE Advanced HetNet Benefits!

Presentation from Qualcomm Webinar, LTE-Advanced Hetnet benefits.


Qualcomm is undisputed leader in the LTE chipsets and have been pushing hard for the next generation LTE-A chipsets. Here is a promotional LTE-Advanced Video on Youtube:

Monday 22 August 2011

MU-MIMO (and DIDO)

Late last month a guy called Steve Perlman announced of a new technology called DIDO (Distributed-Input-Distributed-Output) that could revolutionise the way wireless transmission works and can help fix the channel capacity problem as described by Shannon's formula. A whitepaper describing this technology is available here.

I havent gone through the paper in any detail nor do I understand this DIDO very well but what many experienced engineers have pointed out is that this is MU-MIMO in disguise. Without going into any controversies, lets look at MU-MIMO as its destined to play an important part in LTE-Advanced (the real '4G').

Also, I have been asked time and again about this Shannon's channel capacity formula. This formula is better known by its name Shannon-Hartley theorem. It states:

C <= B log2 (1 + S/N)
where:
C = channel capacity (bits per second)
B = bandwidth (hertz)
S/N = Signal to Noise ratio (SNR)

In a good channel, SNR will be high. Take for example a case when SNR is 20db then log2 (1 + 100) = 6.6. In an extremely noisy channel SNR will be low which would in turn reduce the channel capacity.

In should be pointed out that the Shannon's formula holds true for all wireless technologies except for when multiuser transmission like MU-MIMO (or DIDO) is used.

Anyway, I gave a simple explanation on MU-MIMO before. Another simple explanation of what an MU-MIMO is as explained in this video below:




The picture below (from NTT) gives a good summary of the different kinds of MIMO technology and their advantages and disadvantages. More details could be read from here.

Click to enlarge

As we can see, MU-MIMO is great but it is complex in implementation.

Click to enlarge

Multiuser MIMO technology makes it possible to raise wireless transmission speed by increasing the number of antennas at the base station, without consuming more frequency bandwidth or increasing modulation multiple-values. It is therefore a promising technology for incorporating broadband wireless transmission that will be seamlessly connected with wired transmission in the micro waveband (currently used for mobile phones and wireless LAN, and well suited to mobile communications use), where frequency resources are in danger of depletion. Since it also allows multiple users to be connected simultaneously, it is seen as a solution to the problem specific to wireless communications, namely, slow or unavailable connections when the number of terminals in the same area increases (see Figure 9 above).

There is a good whitepaper in NTT Docomo technical journal that talks about Precoding and Scheduling techniques for increasing the capacity of MIMO channels. Its available here. There is also a simple explanation of MIMO including MU-MIMO on RadioElectronics here. If you want to do a bit more indepth study of MU-MIMO then there is a very good research paper in the EURASIP Journal that is available here (Click on Full text PDF on right for FREE download).

Finally, there is a 3GPP study item on MIMO Enhancements for LTE-Advanced which is a Release-11 item that will hopefully be completed by next year. That report should give a lot more detail about how practical would it be to implement it as part of LTE-Advanced. The following is the justification of doing this study:

The Rel-8 MIMO and subsequent MIMO enhancements in Rel-10 were designed mostly with homogenous macro deployment in mind. Recently, the need to enhance performance also for non-uniform network deployments (e.g. heterogeneous deployment) has grown. It would therefore be beneficial to study and optimize the MIMO performance for non-uniform deployments where the channel conditions especially for low-power node deployments might typically differ from what is normally encountered in scenarios considered so far.

Downlink MIMO in LTE-Advanced has been enhanced in Release 10 to support 8-layer SU-MIMO transmission and dynamic SU-MU MIMO switching. For the 8-tx antenna case, the CSI feedback to support downlink MIMO has been enhanced with a new dual-codebook structure aimed at improving CSI accuracy at the eNB without increasing the feedback overhead excessively. Precoded reference symbols are provided for data demodulation, allowing arbitrary precoders to be used by the eNB for transmission. In many deployment scenarios, less than 8 tx antennas will be employed. It is important to focus on the eNB antenna configurations of highest priority for network operators.

The enhancement of MIMO performance through improved CSI feedback for high priority scenarios not directly targeted by the feedback enhancements in Release 10, especially the case of 4 tx antennas in a cross-polarised configuration, in both homogeneous and heterogeneous scenarios should be studied.

MU-MIMO operation is considered by many network operators as important to further enhance system capacity. It is therefore worth studying further potential enhancement for MU-MIMO, which includes UE CSI feedback enhancement and control signaling enhancement. Furthermore, open-loop MIMO enhancements were briefly mentioned but not thoroughly investigated in Rel-10.

In addition, the experience from real-life deployments in the field has increased significantly since Rel-8. It would be beneficial to discuss the experience from commercial MIMO deployments, and identify if there are any potential short-comings and possible ways to address those. For example, it can be discussed if robust rank adaptation works properly in practice with current UE procedures that allow a single subframe of data to determine the rank. In addition the impact of calibration error on the performance could be discussed.

This work will allow 3GPP to keep MIMO up to date with latest deployments and experience.


Saturday 20 August 2011

Lobbying for more Spectrum

The following Video is prepared by Mobile Future which is a coalition in the US of some major companies and have been lobbying for increase in the availability of the Spectrum.


Friday 19 August 2011

Patent Wars Part 2 - Who is suing whom

Continuing from the earlier post on the Patent Wars, here is a chart on who is suing whom.


Via: ReadWrite Mobile & Reuters

Wednesday 17 August 2011

Patent Wars!

Patent wars has picked up force in the recent few months. Last week the Samsung Galaxy S2 Android phone was banned from the EU due to a suit from Apple but this ban has now been lifted. HTC has sued Apple over patents infringement and is asking for a ban in the US.

Patents are becoming more and more important. In June, Apple and Microsoft (once cut-throat rivals) teamed up with four other companies to pay $4.5 billion for the 6,000 patents held by the bankrupt Nortel Networks. This works out to $750,000 a patent. Google is now in the process of buying Motorola

NY Times report says:

Motorola Mobility in no small part because of its stockpile of 17,000 patents. The patent portfolio, some analysts estimate, could represent more than half of the value of the deal, or more than $400,000 a patent. If so, it was a relative bargain compared to the Apple and Microsoft aquisition of Nortel patents.

In the case of Motorola, Google was under pressure from its big handset partners, including HTC and Samsung, to protect them from patent-infringement suits based on their use of Google’s Android software. And Motorola has an impressive collection of mobile phone patents, a powerful weapon in patent negotiations.

Handset makers and mobile carriers are certainly hoping that Google’s purchase of Motorola will ease tensions in the smartphone market — a patent armistice among rival powers. Verizon on Tuesday welcomed the deal as a move that might well “bring some stability to the ongoing smartphone patent disputes,” John Thorne, senior vice president and deputy general counsel, said in a statement. Verizon Wireless, owned by the Vodafone Group and Verizon Communications, sells both Android-powered phones and iPhones.

In a recent blog post, David Drummond, Google’s chief legal officer, wrote that a modern smartphone might be susceptible to as many as 250,000 potential patent claims (see picture below), depending on how broadly those patents and claims were interpreted.

There was some interesting analysis on the Google Motorola deal by one Josh Pritchard in Quora:

Assuming Google would find value in the patent portfolio and not the operating businesses, an acquisition would presumably only make sense if Google had another partner (or partners), like HTC or Samsung, that wanted Motorola Mobility's operating businesses. If they could work out an arrangement with Google getting the patents and a partner (or partners) taking the other assets, then I'll argue that an acquisition could make a lot of sense based on a sum of the parts analysis.

Motorola Mobility has ~$3.2B in cash (~$170M are hiding as "cash deposits" on a separate line in the balance sheet, and are easily overlooked) with another $225M in additional payments from MSI still pending. They have $2.4B in deferred tax assets, though without reasonable expectations for operational profitability, they carry a $2.3B valuation allowance (again, easily overlooked). If the patents portfolio is worth anywhere near what Google [and Intel] bid on the Nortel patents, say $3.5B, then the sum of those parts is well over $11B in potential value. That's before assigning *any* value to the mobile and set-top operating businesses themselves.

But the operating businesses are almost certainly not worthless. They are set to generate ~$14B in revenue this year and the mobile business, with 41% Y/Y growth, is finally set to become profitable in Q4 of this year... if you believe the company's estimates. If a partner of Google's could reasonably expect to consume the operating businesses and then use their scale and/or superior supply chain to quickly bring them to even greater profitability, it's easy to imagine them being willing to pay at least some fraction of this year's revenue for the businesses, separate from the cash and tax assets. A multiple of .25X on this year's sales would be $3.5B. Seems low.

In total, that's in the neighborhood of $15B in value for a company that currently has a market cap under $7B. So, one might conclude that Google and its partner(s) could pay somewhere between those two numbers, providing a significant premium to market while still acquiring the assets below their fair value.

Of course, there are some restrictions on what MMI can do in its first 24 months as an independent entity, per the terms of the Tax Sharing Agreement documented in the 10-12B/A from the separation in January (when MOT became MSI and MMI). Per my understanding of those terms, if MMI takes actions that compromise the tax-free standing of the separation, as an outright acquisition might do, then they would be on the hook for any resulting tax liabilities. However, as the agreement states, "Though valid as between the parties, the Tax Sharing Agreement is not binding on the IRS" -- and, moreover, I believe there is quite a bit of leeway in terms of how an agreement could be structured in order to preserve the tax-free standing of the separation.


Whatever the case, a Twitter joke suggested that is people would want to retain jobs in Motorola, they better dress up as Patents and go to work.

Finally, patent pools is a good idea and can avoid lots of potential lawsuits and counter-suits. One such company very active in promoting a pool is Sisvel. A presentation from them in the LTE World Summit is embedded below.