Scalable UMTS (S-UMTS) to accelerate GSM Refarming

Looks like a good idea from LTE will possibly be applied to UMTS/HSPA and it will also help accelerate the re-farming of GSM spectrum. A recent presentation from Qualcomm below:

Available to download from here.

Mobile Broadband Speeds: How is 4G different from 3G?

I wrote this answer on Quora and as of yesterday there were 20+ upvotes. So here is an embed for the same:

Read Quote of Zahid Ghadialy's answer to Mobile Broadband: How is 4G different from 3G? on Quora

On Signalling Storm... #LTEWS

The Signalling Storm is coming, its not the question of 'if' but when. This was the unanimous message from the Signaling Focus Day of the 8th LTE World Summit 2012. Several high profile outages have been associated to the Signalling storm, NTT Docomo and Verizon being the main one. Luckily the Telenor outage was due to software issues.

The problem is divided into two parts, the Access network part where the Air Interface is the bottleneck and the core network part which can easily be swamped by the overwhelming amount of Signalling due to more intelligent billing system and always on devices with background applications generating much more amount of traffic as would have on an older system. Lets look at them in turn.

Core Network Signalling Storm:

As I reported earlier, Diameter has been highlighted as a way of salvation for the operators with dozens of use cases but due to its immaturity has caused outages and have given it a bad name. As Connected Planet mentions, "According to one signaling expert, launching the iPhone’s browser, for example, instantly sets off about fifteen individual network signaling requests. Beyond that, 4G network software elements supporting increasingly sophisticated mobile service scenarios “talk” to each other at rates that traditional TDM/SS7-based networks never had to deal with." Hopefully a stable implementation of Diameter protocol will help not only solve the signalling storm but will help generate new models for charging and revenue generation.

A presentation by Ed Gubbins of Current Analysis, comparing the big vendors of Diameter Signalling is available here.

Access Network Signalling Storm:

My thinking is that the Core Network Signalling problem will become an issue some years down the road whereas the Access Network Signalling problem will be seen sooner rather than later. In fact for 3G/HSPA the problem is becoming more visible as the market has matured and more and more users are moving towards using smartphones, Since LTE rollouts are in its infancy (in most markets) the problem is still some way away.

One of the reasons for Signalling storm is the incorrect APN name. I reported earlier about Telefonica's approach to solve this problem by using 'Parking APN', see here.

Also embedded below are couple of presentations from the Signalling Focus day that talk about the problem from Access Network point of view

Martin pineiro telecom-personal_focus-day--tues

View more presentations from ceobroadband

Tracking and preparing a network for the oncoming surge in signaling traffic

View more presentations from Zahid Ghadialy

Other Interesting Reading Material

Finally there is an excellent whitepaper from Heavy Reading titled "The Evolution of the Signalling Challenge in 3G & 4G networks", available here to download.

Another excellent article summarising the problem is from Huawei magazine available here.

HSPA vs LTE

Interesting report to remind the differences between HSPA and LTE available here.

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.

Multicarrier and multiband HSPA aggregation

From NSN Whitepaper on HSPA Evolution:

HSPA Release 10 with 4-carrier HSDPA provides a peak downlink data rate of 168 Mbps using 2x2 MIMO (Multiple Input Multiple Output) over the 20 MHz bandwidth. This matches the LTE Release 8 data rates obtained using comparable antenna and bandwidth configurations. A natural next step for the HSPA Release 10 downlink is to further extend the supportable bandwidths to 40 MHz with 8-carrier HSDPA, doubling the Release 10 peak rate to 336 Mbps.

8-carrier HSDPA coupled with 4x4 MIMO doubles the peak rate again to reach 672 Mbps, see Figure 1. The evolution of HSPA beyond Release 10 will push the peak data rates to rival those provided by LTE Advanced.

In addition to increased peak rates, the aggregation of a larger number of carriers improves spectrum utilization and system capacity owing to inherent load balancing between carriers. Additional capacity gains from trunking and frequency domain scheduling will also be seen.

Typical spectrum allocations do not provide 40 MHz of contiguous spectrum. To overcome spectrum fragmentation, HSDPA carrier aggregation allows carriers from more than one frequency band to be combined. 3GPP Release 9 already makes it possible to achieve 10 MHz allocation by combining two 5 MHz carriers from different frequency bands, such as one carrier on 2100 MHz and another on 900 MHz.

The 4-carrier HSDPA of Release 10 extends this further, allowing the aggregation of up to four carriers from two separate frequency bands. Long Term HSPA Evolution allows eight carriers. Typical cases of HSDPA multiband aggregation are shown in Figure 2.

Fast Dormancy in Release-8

Nokia Siemens Networks has collaborated with Qualcomm to carry out the industry’s first successful interoperability test of the new 3GPP standardized Release 8 Fast Dormancy feature. Unlike proprietary approaches to fast dormancy, the new standard allows operators to take full advantage of smart network features such as Cell_PCH without worrying that individual handset settings will ignore network controls.

The test was conducted at Nokia Siemens Networks’ Smart Lab in Dallas using Nokia Siemens Networks’ Flexi Multiradio Base Station and Radio Network Controller and Qualcomm’s QSC7230TM smartphone optimized chipset. The test showed how smartphones can act dynamically, exploiting Cell_PCH on Nokia Siemens Networks’ smart networks or adjusting to Fast Dormancy on other vendors’ traditional networks.

In fact the operators have been getting upset quite for some time because of smartphone hacks that save the UE battery life but cause network signalling congestion. See here.

To explain the problem, lets look at the actual signalling that occurs when the UE is not transmitting anything. Most probably it gets put into CELL_PCH or URA_PCH state. Then when keep alive messages need to be sent then the state is transitioned to CELL_FACH and once done its sent back to CELL_PCH. Now the transitioning back from CELL_FACH (or CELL_DCH) to CELL_PCH can take quite some time, depending on the operator parameters and this wastes the UE battery life.

To get round this problem, the UE manufacturers put a hack in the phone and what they do is that if there no data to transmit for a small amount of time, the UE sends RRC Signalling Connection Release Indication (SCRI) message. This message is supposed to be used in case when something is gone wrong in the UE and the UE wants the network to tear the connection down by sending RRC Connection Release message. Anyway, the network is forced to Release the connection.

If there is another requirement to send another keep alive message (they are needed for lots of apps like Skype, IM's, etc.) the RRC connection would have to be established all over again and this can cause lots of unnecessary signalling for the network causing congestion at peak times.

To speed up the transitioning to CELL_PCH state in Release-8 when the UE sends SCRI message, its supposed to include the cause value as "UE Requested PS Data session end". Once the network receives this cause it should immediately move the UE to CELL_PCH state.

This is a win win situation for both the network and the UE vendors as long as a lot of UE's implement this. The good thing is that even a pre-Rel8 UE can implement this and if the network supports this feature it would work.

GSMA has created a best practices document for this feature which is embedded below.

GSMA: Fast Dormancy Best Practices

View more documents from Zahid Ghadialy

Further Reading:

• UMTS State Switching and Fast Dormancy Evolution - Martin Sauter
• RP-090941 - System impact of poor proprietary Fast Dormancy implementations
• RP-090942 - Clarification on Enhanced SCRI approach for fast dormancy
• RP-090960 - Configuration of Fast Dormancy
• R2-096882 - Changes to Release-8 Fast Dormancy

RF Pattern Matching adopted in 3GPP Release-10

RF Pattern Matching is now a recognized unique location method in standards that provides carriers and OEMs with the ability to offer high accuracy location-based services that traditionally haven’t been available with low-accuracy Cell-ID based technologies. RF Pattern Matching will be incorporated into Release 10 of the 3G UMTS specifications, expected to become final in late 2010 or early 2011. This will also set the stage for opportunities to incorporate RF Pattern Matching into LTE and other future air interfaces.


“The decision to incorporate RF Pattern Matching into the 3G UMTS specifications is needed for all service providers wanting to provide the highest-SLA option for LBS as it gives them more credible options for public safety and commercial applications,” said Manlio Allegra, president and chief executive officer at Polaris Wireless. “This level of LBS accuracy will create an improved user experience for wireless customers, which ultimately generates additional revenue streams for carriers and other enterprises offering LBS applications.”


Polaris WLS™ is a patent-protected implementation of RF Pattern Matching, which provides the best network-based location performance in urban and indoor settings and is a perfect complement to A-GPS, enabling a best-in-class hybrid solution. Polaris’ WLS™ works without the RF Pattern Matching definition in standards, but standardization through 3GPP allows for future performance enhancements and provides flexibility for the solution and carrier implementations. Polaris’s current WLS products will continue to operate within existing standards.


By being included in the 3G UMTS standard, Polaris’ location technology has received further validation as one of the most accurate in the world. Polaris will now be considered a preferred provider to Tier 1 carriers and infrastructure vendors who want to add a high accuracy location solution to their technology mix that meets the new 3GPP standard.


The FCC is currently considering new E911 Phase II regulations that would improve indoor location capabilities for first responders. Using RF Pattern Matching, Polaris’ WLS™ software solution enables carriers and OEMs to be prepared to meet these new FCC requirements with little or no investment in new infrastructure or hardware.

RF Pattern Matching Discussion document presented in 3GPP is embedded below:

RF Pattern Matching Location Methods

View more presentations from Zahid Ghadialy.

SIMFi = SIM with WiFi

Since the beginning of this year, Sagem Orga and Telefonica have been working on next generation SIM card called SIMFi.

With SIMFi, you can convert a phone into a WiFi hotspot. The phone would use HSPA/LTE for data connectivity and at the same time it would broadcast WiFi signals for any equipment to connect to these signals and browse the web. Power consumption information have not been mentioned which I am sure would be a problem for the phone.

SIMFi Removes the need for additional accessories to facilitate transmission services (e.g. MiFi, USB modem, PCMCIA…) and can make connectivity a lot simpler, straigtforward and cheaper.

SIMFi specifications

• SIM card compatible with the latest telecom specifications.
• SIM card: ISO 2FF plug-in
• The mobile phone does not need any special features.
• Modem WiFi integrated in the SIM card, works with 802.11b.
• The modem is guided by the SIM card's tools.
• Energy-saving features (works with 2G and 3G).
• The aerial is adaptable, allowing short- and long-range operations (from 2 cm to 30 m) managed by the SIM card's tools.

Femtocell Interference Management in real life

Couple of years back we blogged about the Femtocell Inteference in Macro network. Since then things have moved on a long way. There are commercial rollouts happening with Vodafone leading the way. Yesterday, I was reading Prof. Simon Saunders article on Femtocell and the following struck me.

A major technical challenge that femtocell designers initially faced was the need to manage potential interference. It takes up to two years to install conventional base stations, during which time radio engineers meticulously plan a station’s position and radio characteristics to avoid interference. However, such an approach is not viable in the case of femtocells, deployed potentially in their millions at random. Automating a process conducted by radio engineers was no mean feat and simply would not have been possible a few years ago.

Fortunately, the fact that the walls of buildings keep 3G signals out and keep the femtocell’s signals in provides strong inherent interference mitigation for indoor femtocells. Extensive studies have shown that proper implementation of a few key techniques to reduce interference can take advantage of this attenuation in an intelligent manner. Such techniques include frequent monitoring of the cell’s surrounding radio environment combined with adaptive power control. Indoor users gain faster data rates, as do outdoor users who now operate on less congested cells, while it costs less for operators to deliver higher overall network capacity. Large-scale, real-world deployments are demonstrating that these techniques work in practice and even allow new approaches, such as operating 3G networks in the same spectrum as 2G networks.

AT&T has deployed femtocells on the same frequencies as both the hopping channels for GSM macrocells and with UMTS macrocells. They have tested thousands of femtocells, and found that the mitigation techniques implemented successfully minimise and avoid interference. The more femtocells are deployed, the more uplink interference is reduced.

It is very interesting to see that the interference is not causing any problems in real life.


Back in Feb, Femto Forum released a new report on "Interference Management in UMTS Femtocells". A similar report was released in Dec. 08. Then in March they released a similar report for OFDMA (covering both LTE and WiMAX) femtocells. They are interesting reading for those who are interested in this area.


European Union is having a similar program called FREEDOM (Femtocell-based network enhancement by interference management and coordination of information for seamless connectivity ). FREEDOM focuses on:

• Advanced interference-aware cooperative PHY techniques,
• Improvement of the control plane procedures for seamless connectivity, and
• System-level evaluation and hardware demonstrator of the proposed femto-based network architecture.

More info on their website (http://www.ict-freedom.eu/). You can see their scenario document that shows different interference scenarios and also compares different approaches including those of Femto Forum, 3GPP and WiMAX.

Whitepaper: Traffic Management Techniques for Mobile Broadband Networks

Traffic management techniques for mobile broadband networks

View more documents from Zahid Ghadialy.

The report, Traffic Management Techniques for Mobile Broadband Networks: Living in an Orthogonal World,focuses on 3GPP networks and concerns itself specifically with traffic management, including the handling of traffic flows on 3GPP networks in contrast with other network management techniques that operators may deploy (such as offloading, compression, network optimization and other important mechanisms).

Mobile broadband networks are confronted by a number of challenges. In particular, the physical layer in mobile networks is subject to a unique confluence of unpredictable and unrelated, or “orthogonal,” influences. Moreover, mobile broadband networks have some important differences from their fixed brothers and sisters, which lead to different traffic management requirements. Among the most significant differences for purposes of traffic management is the need for more granular visibility to circumstances on the ground. Optimally, traffic management for mobile broadband networks requires visibility to what is occurring (by device or application) at the cell site level and in a timeframe that enables as far as feasible near-time reactions to resolve issues.

With the consumer in mind, an End-to-End (E2E) view of mobile service is critical for traffic management. For example, a consumer using a mobile phone to look up movie listings and purchase tickets considers the E2E service as the ability to see what movie is playing and execute a transaction to purchase tickets. 3GPP has endeavored to standardize increasingly more robust traffic management (Quality of Service, or QoS) techniques for mobile broadband networks with a consumer’s E2E view of QoS. It must be considered, however, that mobile operators typically do not have full control over E2E provisioning of services that depend on mobile broadband Internet access.

Global standards organizations like 3GPP play an important role in the development of traffic management through provisions for addressing QoS, particularly regarding interworking with non-3GPP access mechanisms. These are important new innovations, and the 3G Americas white paper notes that the efforts of standards development organizations should be intensified.

In addition, the configuration of end-user devices and content and applications not provisioned by the network operator not only impacts the experience of the particular user, but potentially other users in a particular cell as well. Efforts to drive further QoS innovations should be mindful of potentially adverse impacts from these sources and support and foster interoperability of third party applications with existing network platforms.

More innovations are needed throughout the mobile broadband ecosystem, in particular by application developers, in order to realize E2E quality of service. Furthermore, transparency in network management practices is important in fostering innovation, but requires a careful balancing to ensure consumer comprehension while safeguarding network reliability. Organizations with technical expertise such as 3G Americas are prepared to help to illuminate and progress the development of these new technologies.

“3G Americas stands ready to assist interested parties in the ongoing development and understanding of traffic management techniques,” said Chris Pearson, President of 3G Americas. “We are mindful that in this hemisphere and elsewhere, the industry has accepted an increasingly active role in addressing questions about service levels and innovation on mobile broadband networks.”

The white paper, Traffic Management Techniques for Mobile Broadband Networks: Living in an Orthogonal World, was written collaboratively by members of 3G Americas and is available for free download on the 3G Americas website at www.3gamericas.org.

UMTS/HSPA State Transition Problems to be solved with LTE

The way UMTS/HSPA is designed is that the Mobile (UE) is always in IDLE state. If there is some data that needs to be transferred then the UE moves to CELL_DCH. If the amount of data is very less then the UE could move to CELL_FACH state. The UE can also move to CELL_PCH and URA PCH if required but may not necessarily do so if the operator has not configured those states.

The problem in UMTS/HSPA is that these state transitions take quite some time (in mobile terms) and can slow down the browsing experience. Martin has blogged about the state transition problems because of the keep alive messages used by the Apps. These small data transfers dont let the UE go in the IDLE state. If they do then whole raft of signalling has to occur again for the UE to go to CELL_FACH or CELL_DCH. In another post Martin also pointed out the sluggishness caused by the UE in CELL_FACH state.


Mike Thelander of the Signals Research Group presented similar story in the recently concluded LTE World Summit. It can be seen from the figure above that moving from IDLE to CELL_DCH is 1-3secs whereas FACH to DCH is 500ms.

In case if some Apps are running in the background, they can be using these keep alive messages or background messages which may be very useful on the PC but for the Mobiles, these could cause unnecessary state transitions which means lots of signalling overhead.

The Apps creators have realised this problem and are working with the Phone manufacturers to optimise their messaging. For example in case of some Apps on mobiles the keep alive message has been changed from 20 seconds to 5 mins.

3GPP also realised this problem quite a while back and for this reason in Release-7 two new features were added in HSPA+. One was Continuous Packet Connectivity (CPC) and the other was Enhanced CELL_FACH. In Release-8 for HSPA+, these features were added in UL direction as well. The sole aim of these features were to reduce the time it would take to transit to CELL_DCH. Since CPC increases the cell capacity as well, more users can now be put in CELL_FACH instead of being sent to IDLE.

An interesting thing in case of LTE is that the RRC states have been simplified to just two states as shown here. The states are IDLE and CONNECTED. The intention for LTE is that all the users can be left in the CONNECTED state and so unnecessary signalling and time spent on transitioning can be reduced.

The preliminary results from the trials (as can also be seen from here) that were discussed in the LTE World Summit clearly show that LTE leads to a capacity increase by 4 times (in the same BW) and also allow very low latency. I am sure that enough tests with real life applications like Skype, Fring and Yahoo IM have not been done but I am hopeful of the positive outcome.

Interesting calculation showing that data cost to operator is €1/per GB

HSPA & LTE: Peak Rates, Average Cell capacity and Round Trip Time

Interesting picture

HSPA finds success with Mobile Broadband Growth

Another GSA report titled "Mobile Broadband Growth - Reports from HSPA Operators Worldwide". As the name suggests, this contains report from different operators on their Mobile Broadband revenues growth.

Some interesting bits from the report:

• According to a report from AdMob, smartphonedata traffic grew 193% year-over-year in the month of February 2010. Smartphonesaccounted for 48% of its traffic in February 2010, up from 35% the year before. AdMobattributed this primarily to iPhoneand Android traffic.
• Deutsche Telekom CEO René Obermann is expected to double revenues by 2015 with €10 billion coming from mobile data traffic. Obermann said it would double the number of 3G smartphonesin the network to around 8 million by the end of 2010
• A recent report by In-Stat, stated that mobile broadband is now the second-largest access technology behind DSL, making up 18% subscribers
• Telia Sonera reported that the strong demand for mobile devices, including mobile broadband and Apple iPhone™, continued. Mobile data traffic in Nordic and Baltic operations increased close to 200% while the number of mobile broadband subscriptions rose by more than 60% during 2009.
• AT&T reported that Text messaging grew 50% YoY and picture messaging grew 130%
• According to IDC's Worldwide Quarterly Mobile Phone Tracker, vendors shipped a total of 54.5 million units Q4 09, up 39.0% from Q4 08. Vendors shipped a total of 174.2m units in 2009, up 15.1% from the 151.4m units in 2008. Converged mobile devices accounted for 15.4% of all mobile phones shipped in 2009, up slightly from 12.7% in 2008
• The number of people subscribing to broadband internet services in Australia grew rapidly with wireless broadband and 3G mobile services continuing strong growth in 2009, according to a new report by ACMA (Australian Communications and Media Authority). 3G now accounts for more than 50% of all mobile subscriptions, an annual increase of 44%. Internet subscriptions reached 8.4 million in June 2009, compared to 7.2 million in June 2008. Broadband subscriptions increased from 5.66 million to 6.72 million in the same period, with wireless subscribers gaining 162% to 2.1 million
• Vodafone's Data traffic has risen 300% in the past two years. Data now represents 11% of all European service revenues. Smartphones represent 20% of handsets sales. Around 40% of the company's European 3G/HSPA networks now support 7.2 Mbps. In the coming 6 months, Vodafone plans to upgrade 20-25,000 sites across Europe to HSPA+
• UK consultancy firm, Coda Research Consultancy, has predicted that mobile data consumption in the US is set to reach 327,000 terabytes a month by 2015, indicating a 40-fold rise in mobile data consumption over 5 years
• Mobile data traffic from PC modems and routers is forecast to increase 4-fold between 2010 and 2014, according to a report by ABI Research. 2,000 petabytes of data will be sent and received in 2010, a figure that will rise to about 8,000 petabytesin 2014
• Semiannual US wireless industry survey was released at CTIA in March 2010 revealing that wireless service revenues totaled $77 billion for the last half of the year. The real growth is coming from wireless data services -mobile Web, text messages, and other non-voice services. In the latter half of last year, revenue for wireless data service totaled > $22 billion, nearly a third of overall wireless services revenue and up 26% YoY. Steve Largent, President and CEO of CTIA, said in a statement. "Mobile broadband will increasingly play a vital role in people’s lives."
• A new study by Juniper Research has forecast that more than 1 in 10 mobile subs will either have a ticket delivered to their mobile phone or buy a ticket with their phone by 2014, representing a five-fold growth over the next five years.
• Strategy Analytics recently forecast that the number of active mobile broadband subscriptions worldwide is expected to rise to around 1.3 billion by 2014
• ABI Research announced that shipments of mobile broadband-enabled consumer products, which includes e-book readers, mobile digital cameras, camcorders, personal media players, personal navigation devices and mobile gaming devices will increase 55-fold between 2008 and 2014 with total shipments reaching 58 million units per year in 2014

HSPA+ to reach 168Mbps in Release-10

Just when we thought that we have squeezed every bit out of HSPA, a surprise waiting is the speeds of upto 168Mbps in the downlink. Going back to the 3G Americas report, there is a section in the end that details HSPA+ enhancements for Rel-10:

Rel-8 introduced dual-carrier HSDPA operation in the downlink while Rel-9 similarly introduced dual-carrier HSUPA operation in the uplink and also enhanced the dual-carrier HSDPA operation by combining it with MIMO.

Further enhanced multi-carrier HSDPA operation is being specified for Rel-10, where the base station will be able to schedule HSDPA transmissions over three or four carriers simultaneously to a single user with the carriers are spread over one or two frequency bands. Solutions specified in earlier releases can be reused to a large extent. The difference is that now it is possible to configure a UE with one primary serving cell and up to three secondary serving cells. As in earlier releases, the secondary serving cells can be activated and deactivated dynamically by the base station using so-called “HS-SCCH orders.” With MIMO transmission on all four carriers, the peak rate would be doubled to 168 Mbps compared to Rel-9 and for typical bursty traffic the average user throughput would also experience a substantial increase.

Remember, I posted a blog on data rates calculation? The maximum data rate in Release-8 HSDPA is 42Mbps. With Dual-carrier operation, this could be doubled to 84Mbps. As you can probably guess, with 4 carriers, this will become 168Mbps ;)

For people who are less technically inclined, can check this Ericsson presentation on HSPA+ data rates. For people who may become sleepless without some technical references can check this report from RAN WG#1 meeting#59. If you are not sure what RAN WG#1 is, check quick tutorial on 3GPP here.

Going back to the 3GPP report, section 5.4 lists the details of 4 carriers HSDPA. It would be interesting to see what happens in cases where initially there were 4 carriers but then in a particular spot it changed to 2 carriers, and vice-versa. People who have yet to work on LTE may not have to worry too much as HSPA is being future proofed against the threats of LTE and WiMAX.

Interestingly enough, HSPA+ offers a better and cleaner solution at the moment especially with regards to voice calls and handing over to GSM then LTE or WiMAX.

It wont come as a surprise if the HSPA+ camp are able to pull out some new tricks from their bag just in time for Release-11.

3G Americas Publishes New Report on Technology choices for Mobile Broadband

3G Americas, a wireless industry trade association representing the GSM family of technologies including LTE, announced that it has published its highly anticipated resource report on 3rd Generation Partnership Project (3GPP) standards and their evolution to IMT-Advanced, or 4G. The white paper, 3GPP Mobile Broadband Innovation Path to 4G: Release 9, Release 10 and Beyond: HSPA+, SAE/LTE and LTE-Advanced, provides in-depth examination of 3GPP technology standards from a technical, business and applications standpoint.

“The 3GPP technology standards deliver mobile connectivity to more than 4 billion users worldwide today and have been developed to continue evolving to higher levels of performance with mobile broadband innovation,” said Chris Pearson, president of 3G Americas. “GSM operators can choose to evolve their networks in ways that best suit their assets and business environments with benefits that offer flexibility, scalability and economic advantages, whether they choose HSPA+ or LTE.”

UMTS-HSPA is the world’s leading 3G technology and is the preferred choice for the majority of wireless operators and subscribers today and into the future. The global demand for wireless data services continues to drive the rapid growth of HSPA technology with 303 commercial HSPA networks and over 454 million UMTS-HSPA subscriptions reported at the end of 2009 by Informa Telecoms & Media. Informa has further projected that by year-end 2012, worldwide subscriptions to UMTS-HSPA will reach nearly 1.4 billion; by year-end 2013, global UMTS-HSPA subscriptions are expected to exceed 2 billion, rising to 2.8 billion by the end of 2014. GSM-UMTS-HSPA subscriptions provide the foundation for future evolutions to 3GPP Release 9, Release 10 and beyond with HSPA+, LTE and LTE-Advanced.

“Wireless data consumption is increasing faster now than ever before,” said Adrian Scrase, 3GPP Head of Mobile Competence Center. “Smartphone usage is experiencing higher volumes and the superior user experience offered by such devices is resulting in quickly rising demand and escalating use of wireless data applications. This is consequently driving the need for continued innovations that are supported by the efficient and successful 3GPP technology path.”

3GPP Mobile Broadband Innovation Path to 4G: Release 9, Release 10 and Beyond: HSPA+, SAE/LTE and LTE-Advanced, is a comprehensive resource intended to assist members of the wireless industry as well as interested members of the general public in understanding details of the work in 3GPP on Release 9 and Release 10. In addition, the report further describes the features of Release 8 that were closed in March 2009.

Release 9, which is targeted for completion by March 2010, will provide increased feature functionality and performance enhancements to both HSPA and LTE. The report reviews additional multi-carrier and MIMO options for HSPA and features and enhancements to support emergency services, location services and broadcast services for LTE. Other Release 9 enhancements include those to support Home NodeB/eNodeB (i.e. femtocells), Self-Organizing/Self-Optimizing Networks (SON) and the evolution of the IP Multimedia Subsystem (IMS) architecture.

LTE will serve to unify the fixed and mobile broadband worlds. As an all IP-based technology, LTE will allow expansion of the Internet experience on mobile devices and deliver multimedia content to the screen of choice. The vast majority of leading operators, device and infrastructure manufacturers support LTE as the mobile broadband technology of the future and, according to Informa Telecoms & Media, 130 global operators have announced trials or intentions to evolve their networks to LTE. Two commercial networks have already been launched in Norway and Sweden by TeliaSonera in 2009 and as many as 20 will be launched in 2010.

“All roads lead to LTE – for GSM, CDMA, newly licensed and potentially even WiMAX mobile operators,” Pearson added. “The appeal of the 3GPP technology roadmap is no longer suited for only GSM operators.”

While work for Release 9 is nearing completion, significant progress has already been made in 3GPP on work for Release 10, which includes LTE-Advanced. In fact, 3GPP already submitted a proposal in October 2009 based on LTE-Advanced for the IMT-Advanced evaluation and certification process led by the International Telecommunication Union (ITU). The ITU has defined requirements that will officially define and certify technologies as IMT-Advanced, or 4G, and is expected to evaluate submitted proposals by standards organizations for potential certification in the 2010 timeframe; certified 4G/IMT-Advanced technology specifications are projected to be published by early 2011.

As part of Release 10, some of the key LTE-Advanced technology enhancements include carrier aggregation, multi-antenna enhancements and relays. Assuming LTE-Advanced is certified to be IMT-Advanced compliant, 3GPP targets completion of the Release 10 specification by year-end 2010.

“The white paper by 3G Americas provides an excellent overview of the work by 3GPP in determining the standards on the path to 4G,” Scrase said.

The popular white paper, 3GPP Mobile Broadband Innovation Path to 4G: Release 9, Release 10 and Beyond: HSPA+, SAE/LTE and LTE-Advanced, was written collaboratively by members of 3G Americas and is available for free download here.

Technologies and Standards for TD-SCDMA Evolutions to IMT-Advanced

Picture Source: http://www.itu.int/dms_pub/itu-t/oth/21/05/T21050000010003PDFE.pdf

This is a summary of a paper from IEEE Communications Magazine, Dec 2009 issue titled "Technologies and Standards for TD-SCDMA Evolutions to IMT-Advanced" by Mugen Peng and Wenbo Wang of Beijing University of Posts and Telecommunications with my own comments and understanding.

As I have blogged about in the past that China Mobile has launched TD-SCDMA network in China and the main focus to to iron out the basic problems before moving onto the evolved TD-SCDMA network. Couple of device manufacturers have already started working on the TD-HSPA devices. Couple of months back, 3G Americas published a whitepaper giving overview and emphasising the advantages of TDD flavour of LTE as compared to FDD. The next milestone is the IMT-Advanced that is under discussion at the moment and China has already proposed TD-LTE-Advanced which would be compatible with the TD-SCDMA technology.

For anyone who does not know the difference between TDD, FDD and TD-SCDMA please see this blog.

The TD-SCDMA technology has been standardised quite a while back but the rollout has been slow. The commercial TD-SCDMA network was rolled out in 2009 and more and more device manufacturers are getting interested in the technology. This could be due to the fact that China Mobile has a customer base of over 500 million subscribers. As of July 2009 over 100 device manufacturers were working on TD-SCDMA technology.

The big problem with TD-SCDMA (as in the case of R99 3G) is that the practical data rate is 350kbps max. This can definitely not provide a broadband experience. To increase the data rates there are two different approaches. First is the Short Term Evolution (STE) and the other is Long Term Evolution (LTE).

The first phase of evolution as can be seen in the picture above is the TD-STE. This consists of single carrier and multi-carrier TD-HSDPA/TD-HSUPA (TD-HSPA), TD-MBMS and TD-HSPA+.

The LTE part is known as TD-LTE. There is a definite evolution path specified from TD-SCDMA to TD-LTE and hence TD-LTE is widely supported by the TD-SCDMA technology device manufacturers and operators. The target of TD-LTE is to enhance the capabilities of coverage, service provision, and mobility support of TD-SCDMA. To save investment and make full use of the network infrastructure available, the design of TD-LTE takes into account the features of TD-SCDMA, and keeps TD-LTE backward compatible with TD-SCDMA and TD-STE systems to ensure smooth migration.

The final phase of evolution is the 4G technology or IMT-Advanced and the TD-SCDMA candidate for TD-LTE+ is TD-LTE-Advanced. Some mature techniques related to the TD-SCDMA characteristics, such as beamforming (BF), dynamic channel allocation, and uplink synchronization, will be creatively incorporated in the TD-LTE+ system.

Some academic proposals were also made like the one available here on the future evolution of TD-SCDMA but they lacked the industry requirements and are just useful for theoretical research.

The standards of TD-SCDMA and its evolution systems are supervised by 3GPP in Europe and by CCSA (Chinese Cellular Standards Association) in China. In March 2001 3GPP fulfilled TD-SCDMA low chip rate (LCR) standardization in Release 4 (R4). The improved R4 and Release 5 (R5) specifications have added some promising functions including HSDPA, synchronization procedures, terminal location (angle of arrival [AOA]-aided location), and so on.

When the industry standardizations supervised by CCSA are focusing on the integration of R4 and R5, the N-frequency TD-SCDMA and the extension of HSDPA from single- to multicarrier are presented. Meanwhile, some networking techniques, such as N-frequency, polarized smart antenna, and a new networking configuration with baseband unit plus remote radio unit (BBU+RRU), are present in the commercial application of TD-SCDMA.

TD-SCDMA STE

For the first evolution phase of TD-SCDMA, three alternative solutions are considered. The first one is compatible with WCDMA STE, which is based on HSDPA/HSUPA technology. The second is to provide MBMS service via the compatible multicast broadcast single-frequency network (MBSFN) technique or the new union time-slot network (UTN) technique. The last is HSPA+ to achieve similar performance as LTE.

On a single carrier, TD-HSDPA can reach a peak rate of 2.8 Mb/s for each carrier when the

ratio of upstream and downstream time slots is 1:5. The theoretical peak transmission rate of a three-carrier HSDPA system with 16-quadrature amplitude modulation (QAM) is up to 8.4 Mb/s.

Single-carrier TD-HSUPA can achieve different throughput rates if the configurations and parameters are varied, including the number of occupied time slots, the modulation, and the transport block size in bytes. Considering the complexity of a terminal with several carriers in TD-HSUPA, multicarrier is configured in the Node B, while only one carrier is employed in the terminal.

In Rel-7 based TD-HSPA+, In order to match the performance of orthogonal frequency-division multiple access (OFDMA)-based TD-LTE systems, some advanced techniques are utilized, such as multiple-input multiple-output (MIMO), polarized BF, higher modulation and coding schemes (64-QAM is available), adaptive fast scheduling, multicarrier techniques, and so on. Theoretically, 64-QAM can improve performance by a factor of 1.5 compared to the current 16-QAM; for single-carrier the peak rate reaches 4.2 Mb/s, and three-carrier up to 12.6 Mb/s.

For the MIMO technique, double transmit antenna array (D-TxAA), based on the pre-coding method at the transmitter, has been employed in frequency-division duplex (FDD)-HSPA+ systems, while selective per antenna rate control (S-PARC), motivated by the Shannon capacity limit for an open loop MIMO link, has been applied in TD-HSPA+ systems.

TD-SCDMA LTE

The TD-SCDMA LTE program was kicked off in November 2004, and the LTE demand report was approved in June 2005. The LTE specified for TD_SCDMA evolution is named TD-LTE.

LTE systems are supposed to work in both FDD and TDD modes. LTE TDD and FDD modes have been greatly harmonized in the sense that both modes share the same underlying framework, including radio access schemes OFDMA in downlink and SC-FDMA in uplink, basic subframe formats, configuration protocols, and so on.

TD-LTE trials have already started last year with some positive results.

TD-SCDMA LTE+

IMT-Advanced can be regarded as a B3G/4G standard, and the current TD-SCDMA standard migrating to IMT-Advanced can be regarded as a thorough revolution. TD-LTE advanced (TD-LTE+) is a good match with the TD-SCDMA revolution to IMT-Advanced.

It is predicted that the future TD-SCDMA revolution technology will support data rates up to approximately 100 Mb/s for high mobility and up to approximately 1 Gb/s for low mobility such as nomadic/local wireless access.

Recently, some advanced techniques have been presented for TD-LTE+ in China, ranging from the system architecture to the radio processing techniques, such as multi-user (MU)-BF, wireless relaying, and carrier aggregation (CA).

For MU-BF see the paper proposed by Huawei, CHina Mobile and CATT here (http://www.3gpp.org/ftp/tsg_ran/WG1_RL1/TSGR1_55b/Docs/R1-090133.zip).

For Wireless Relaying see the ZTE paper here (http://www.3gpp.org/ftp/tsg_ran/WG1_RL1/TSGR1_56b/Docs/R1-091423.zip).

To achieve higher performance and target peak data rates, LTE+ systems should support bandwidth greater than 20 MHz (e.g., up to 100 MHz). Consequently, the requirements for TD-LTE+ include support for larger transmission bandwidths than in TD-LTE. Moreover, there should be backward compatibility so that a TD-LTE user can work in TD-LTE+ networks. CA is a concept that can provide bandwidth scalability while maintaining backward compatibility with TD-LTE through any of the constituent carriers, where multiple component carriers are aggregated to the desired TD-LTE+ system bandwidth. A TD-LTE R8 terminal can receive one of these component carriers, while an TD-LTE+ terminal can simultaneously access multiple component carriers. Compared to other approaches, CA does not require extensive changes to the TD-LTE physical layer structure and simplifies reuse of existing implementations. For more on Carrier Aggregation see CATT, LGE and Motorola paper here (http://www.3gpp.org/ftp/tsg_ran/WG1_RL1/TSGR1_56b/Docs/R1-091655.zip).

Finally, there are some interesting developments happening in the TD-SCDMA market with bigger players getting interested. Once a critical mass is reached in the number of subscribers as well as the manufacturers I wouldnt be surprised if this technology is exported beyond the Chinese borders. With clear and defined evolution path this could be a win-win situation for everyone.

MBMS and AMR-WB

Nokia publicly underlined its commitment to broadcast-mobile-TV standard DVB-H with the recent unveiling of the mobile TV edition of the Nokia 5330 and its pretax, presubsidy price tag of €155 (US$230), after some in the industry had questioned its enthusiasm for launching new DVB-H devices. Nokia also quelled any suggestions that it might start supporting the MBMS standard with its future device launches.

The price is a massive drop from the €550 price tag carried by Nokia’s last fully DVB-H-compatible handset, the N96, which launched in 3Q08. So the official line from Nokia is this: “All is well on the good ship DVB-H.”

Read more here.

Meanwhile, In China, China Unicom has launched 3G telecom services in 268 cities across the country, said Li Gang, another deputy general manger for Unicom Group, noting that the WCDMA network supports a 14Mbps download data transmission speed and a 7.2Mbps upload data transmission speed.

Notably, the carrier has adopted the most advanced R6 technology in its core WCDMA network to smooth a WCDMA-to-EPS migration in the future, according to Mr. Zhang.

The China Unicom network is expected to support MBMS and HSPA+64QAM technology in the first phase of a further evolution, shore up a HSPA+MIMO technology in the Phase II evolution, and prompt a LTE technology in the Phase III evolution, said Mr. Zhang, adding that the network will present a 100Mbps download speed and a 50Mbps upload speed after the Phase III evolution.

Read more here.
Back in September, Orange Moldova announced the launch of the world's first mobile telephone service offering high-definition (HD) sound. The service will provide customers with a significantly improved quality of service when making calls. Unlike for other mobile technologies such as multimedia capabilities, this is the first time since the 1990s that mobile voice technologies have been subject to a significant evolution.

This is the second step in Orange’s HD voice strategy, following on from the launch of a high-definition voice service for VoIP calls in 2006. Over 500,000 Livephone devices have already been sold in France and the range will be extended to other Orange countries over the coming months.

The first mobile handset integrating high-definition voice capability that will be launched by Orange Moldova is the Nokia 6720c. This innovative handset integrates the new WB-AMR technology, which is widely expected within the industry to become a new standard for mobile voice communications.

Thanks to the Adaptive Multi Rate-WideBand (AMR-WB) codec, double the frequency spectrum will be given over to voice telephony over traditional voice calling. Orange boasts that the result is "near hi-fi quality" and "FM-radio quality", which seems an odd comparison.

Updates from GSMA Asia Mobile Congress 09 - Day 2

Summary of interesting facts from the GSMA Mobile Asia Congress 09, Via Tomi Ahonen's, Communities Dominate Brands:

• 55% of Japan has migrated past 3G to 3.5G
• Japanese mobile content industry is worth 14 Billion dollars annually
• 50% of mobile data in Japan is consumed in the home, the peak time for mobile data consumption is between 9 PM and 10 PM; and smartphone users consume 10 times more data than non-smartphone users.
  
• Japan's Softbank will turn off their 2G network already in March of next year, 2010.
• Allen Lew, Singtel's CEO, said that in Singapore almost 50% of smartphone owners are shifting web surfing activity away from PCs.
  
• Jon Fredrik Baksaas, Telenor's President and CEO, spoke about the eco-friendly initiatives they have, such as solar powered cellular network base stations etc, but an interesting tidbit that came out, is that in Europe, Telenor has installed 870,000 household electricity meters that are remote digital meters and operate on the GSM cellular network, in Sweden. As Sweden's population is only about 7 million people that is probably a third of all households.
  
• Rajat Mukarji of Idea (one of India's largest mobile operators), told us of the Indian market, where the average price of a voice minute is 1 cent (US). He Mr Mukarji also said that in India mobile is the first screen, not the fourth screen; and mobile is the first internet connectivity opportunity for most people of India.
• Tony Warren, GM of Regulatory Affairs at Telstra, told that 60% of phones in Australia are 3G already, and over half of mobile data is now non-SMS type of more advanced mobile data. And he said that MMS is experiencing enormous growth, grew 300% in the past year.

You can read the summary of first day here.

Read the complete report here.