Flexible RLC in Release 7 and Release 8

In R99, RLC packets had to be relatively small to avoid the retransmission of very large packets in case of transmission errors. Another reason for the relatively small RLC packet size was the need to provide sufficiently small step sizes for adjusting the data rates for Release 99 channels.

The RLC packet size in Release 99 is not only small, but it is also fixed for Acknowledged Mode Data and there are just a limited number of block sizes in UM Data. This limitation is due to transport channel data rate limitations in Release 99. The RLC payload size is fixed to 40 bytes in Release 99 for Acknowledged Mode Data. The same RLC solution is applied to HSDPA Release 5 and HSUPA Release 6 as well: the 40-byte packets are transmitted from RNC to the base station for HSDPA. An additional confi guration option to use an 80-byte RLC packet size was introduced in Release 5 to avoid extensive RLC protocol overhead, L2 processing and RLC transmission window stalling. With the 2 ms TTI used with HSDPA this leads to possible data rates being multiples of 160 kbps and 320 kbps respectively.

As the data rates are further increased in Release 7, increasing the RLC packet size even further would significantly impact on the granularity of the data rates available for HSDPA scheduling and the possible minimum data rates.

3GPP HSDPA and HSUPA allow the optimization of the L2 operation since L1 retransmissions are used and the probability of L2 retransmissions is very low. Also, the Release 99 transport channel limitation does not apply to HSDPA/HSUPA since the L2 block sizes are independent of the transport formats. Therefore, it is possible to use fl exible and considerably larger RLC sizes and introduce segmentation to the Medium Access Control (MAC) layer in the base station.

This optimization is included for downlink in Release 7 and for uplink in Release 8 and it is called flexible RLC and MAC segmentation solution. The RLC block size in fl exible RLC solution can be as large as an Internet Protocol (IP) packet, which is typically 1500 bytes for download. There is no need for packet segmentation in RNC. By introducing the segmentation to the MAC, the MAC can perform the segmentation of the large RLC PDU based on physical layer requirements when needed. The fl exible RLC concept in downlink is illustrated in Figure above.


There is a lot of interesting information in R&S presentation on HSPA. See here.

Main source of the content above and for further information see: LTE for UMTS: OFDMA and SC-FDMA Based Radio Access

Enhanced UL for CELL_FACH state in Release 8

Users should always be kept in the state that gives the best trade-off between data rate availability, latency, battery consumption and usage of network resources. As a complement to the data rate enhancements made to the dedicated state (CELL_DCH), 3GPP has also made significant enhancements to the common states (URA_PCH, CELL_PCH and CELL_FACH). Release 7 introduced HSDPA mechanisms in the common states in order to improve their data rates, latency and code usage. Release 8 introduces corresponding enhancements in the uplink, allowing base stations to configure and dynamically manage up to 32 common Enhanced Uplink resources in each cell.



This enhancement improves latency and data rates for keep-alive messages (for example, from VPN or messenger applications) as well as web-browsing events, providing a seamless transition from EUL in common state to EUL in dedicated state.

As a further improvement of the CELL_FACH state, Release 8 introduces discontinuous reception (DRX), which significantly reduces battery consumption. DRX is now supported in all common and dedicated states.



Enhanced FACH and RACH bring a few performance benefits:

• RACH and FACH data rates can be increased beyond 1 Mbps. The end user could get immediate access to relatively high data rates without the latency of channel allocation.
• The state transition from Cell_FACH to Cell_DCH would be practically seamless. Once the network resources for the channel allocation are available, a seamless transition can take place to Cell_DCH since the physical channel is not changed.
• Unnecessary state transitions to Cell_DCH can be avoided when more data can be transmitted in Cell_FACH state. Many applications create some background traffic that is today carried on Cell_DCH. Therefore, Enhanced RACH and FACH can reduce the channel element consumption in NodeB.
• Discontinuous reception could be used in Cell_FACH to reduce the power consumption. The discontinuous reception can be implemented since Enhanced FACH uses short 2 ms TTI instead of 10 ms as in Release 99. The discontinuous reception in Cell_FACH state is introduced in 3GPP Release 8.

For more information see: LTE for UMTS: OFDMA and SC-FDMA Based Radio Access

Net Neutrality: Good or Bad?

I am not sure what the right answer to this question is? There will be winners and losers in either case.

FCC (Federal Communications Commission) chairman Julius Genachowski has just outlined his much-awaited plan for Internet neutrality. If the plan is approved it would drag the wireless operators in the US into the public regulatory arena occupied by their wired cousins who have recently had to account for their neutrality policies to the FCC.

The proposed policy outlined today by Genachowski will mean the FCC will get to poke and pry into mobile operators' business policies and rule on how well they conform to FCC guidelines on neutrality in the same way that wiredtelcos must. The FCC will also impose new and tighter neutrality behaviour on the big phone companies including Verizon and AT&T.

In detail: Genachowski has reaffirmed the long-standing (since 2005) broadband principles that will now be formalised by the FCC.

• That consumers are entitled to access the lawful Internet content of their choice.
• That they are also entitled to run applications and use services of their choice, subject to the needs of law enforcement.
• That they are entitled to connect their choice of legal devices that do not harm the network.
• And that they are entitled to competition among network providers, application and service providers, and content providers.

Genachowski has added two extra principles. Internet access providers can't discriminate against particular Internet content or applications: and they must ensure that Internet access providers are transparent about the network management practises they implement.

"The rule-making process will enable the commission to analyse fully the implications of the principles for mobile network architectures and practises, and how, as a practical matter, they can be fairly and appropriately implemented," Genachowski said today.

U.S. phone companies may be forced to open their wireless networks to rival Internet services like Skype and Google Voice under the proposal. The proposal, if adopted, would be a victory for consumer advocates and big Internet companies like Google Inc at the expense of telecom operators like AT&T Inc, Verizon Communications and Sprint Nextel Corp.

"The risk to the wireless carriers is that they won't be able to stop customers from using free voice and text services like Skype or Google voice," said Bernstein analyst Craig Moffett. "Voice and text are where they make all of their money."

The FCC has already been examining why Apple Inc rejected Google Voice for use on iPhone, sold by AT&T.

The new proposal could result in mobile customers cutting their phone bills by opting for minimum carrier voice plans and doing without text-messaging plans if they use mobile voice and text services from Skype and Google.

Piper Jaffray analyst Christopher Larsen downplayed the risk, saying that if they have to, operators would be sure to find a way to change their fees in order to maintain profits.
Advocates of Net neutrality have long argued that service providers must be barred from blocking or slowing Internet traffic based on the content being sent or downloaded.

But service providers say the increasing volume of bandwidth-hogging services -- such as video sharing -- puts pressure on them as it requires active network management, and some argue that Net neutrality could stifle innovation.

AT&T, the No. 2 U.S. mobile service, said it was concerned about an extension of Net neutrality rules to the competitive mobile industry.

The new regulations would limit consumer choices and "affect content providers, application developers, device manufacturers and network builders," said an executive at Verizon, which owns the No. 1 mobile service with Vodafone Group Plc.

Wireless trade group CTIA, whose members include AT&T, Verizon Wireless and Sprint Nextel, said it was concerned the proposal would have "unintended consequences." Leading Cable provider Comcast Corp said it was pleased Genachowski "recognized that networks need to be managed."

Exactly my thoughts (but with proper technical terms, language and analysis ;) by Gary Kim in IP Communications:

In the communications business, rationing is a fact of network life. Since virtually every part of a communications network uses shared resources, and in a market where users do not want to pay too much for access to those resources, rationing of network resources is necessary.

Shared finite resources always pose a usage problem. Known as the "tragedy of the commons," the economic problem is that multiple individuals, acting independently, solely and rationally when using a common resource can ultimately destroy the shared limited resource.

Some people argue that this problem cannot exist with the Internet, which is virtually infinitely expansible. But that misses the point. In looking at shared resources, the "commons" is the access network's resources, primarily. In other words, the "choke point" is the homeowner's garden hose, not the reservoir.

Some might argue that IP technology, optics, Moore's Law and competition upend the traditional "scarcity" value of access bandwidth. Certainly it helps. Currently, most consumers have access to two terrestrial broadband providers, two satellite networks, three, possibly four mobile networks. Then, there are broadband pipes where people work, at school and at many retail locations.

Still, there are some physical and capital investment limits, at least at retail prices consumers seem willing to pay. If consumers are willing to pay much more, they can get almost any arbitrarily-defined amount of access bandwidth. That, after all, is what businesses do.

If consumers resist paying business prices, network investment has to be shared more robustly than it otherwise might.

Given that all network resources are shared, resources are finite. To support retail prices that require such sharing, networks are designed in ways that "underprovision" resources ranging from radio ports to multiplexers to backhaul bandwidth. Based on experience, network designers engineer networks to work without blocking or degradation most of the time, but not necessarily always. Unusual events that place unexpected load on any part of the access network will cause blocking.

Blocking, in other words, is a network management technique. And that's the problem the Federal Communications Commission is going to have as it looks at additional "network freedoms" rules commonly known as "network neutrality." The term itself is imprecise and in fact already covered by the existing FCC rules. One might argue the issue is more the definitions and applications of existing rules that require clarification.

The ostensible purpose of the new rules is to prevent access provider blocking or slowing of any lawful applications, but a rule exists for that. Instead, it appears a primary effect of the rules will be to extend wired network rules to wired providers.

Beyond that, policymakers will have to contend with tragedy of the commons effects. If, in forbidding any traffic shaping (a network management technique) in the guise of "permitting the free flow of bits," rulemakers might set the stage for dramatic changes in industry packaging and prices of Internet access and other applications and services.

U.S. consumers prefer "flat rate billing" in large part because of its predictability of cost. But highly differentiated usage, in a scenario where networks cannot be technically managed by any traffic prioritization rules, will lead to some form of metered billing.

If metered billing is not instituted, and if service providers cannot shape traffic at peak hours to preserve network access for all users, then heavy users either have to pay more for their usage patterns, they will have to change their usage patterns, or they might experience some equivalent of "busy hour blocking."

Application providers and "public policy advocates" seem to be happy that new network neutrality rules might be adopted. They might not be so happy if ISPs lose the ability to deny or slow access to network resources. On the voice networks, some actual call blocking is allowed at times of peak usage. Forcing users to redial might be considered a form of traffic shaping, allowing access, but at the cost of additional time, or time-shifted connections.

To the extent that such blocking rules already are impermissible, some other network management techniques must be used. And one way to manage demand is to raise its price, either by increases in flat-rate package prices, by instituting usage-based billing or some other functionally-similar policy.

To avoid the tragedy of the commons problem, in other words, requires raising the end user's understanding of cost to use the shared resource.

Prioritized traffic handling, which assigns users a lower priority in the network once they have reached their fair use level, might be a preferable traffic management technique to slowing any single user's connection, once their individual usage caps have been reached.

When that is done, heavy users experience degradation in service only when competing for resources in a congested situation. For peer-to-peer users, the experienced reduction in throughput will be limited over time.

Only in heavily loaded cells or areas will a peer-to-peer user experience serious issues. Prioritized traffic handling enables operators to focus on dimensioning their networks for normal usage, while still permitting unlimited or "all you can eat" traffic.

Perhaps there are other ways of handling the "rationing," but on a shared network with network congestion, available to users paying a relatively modest amount of money, while a highly-differentiated load being placed on the network by a small number of users, some form of rationing is going to happen.

Perhaps flat rate packaging might still be possible if rationing affects end user credentials, rather than bits and applications or protocols. In other words, instead of "throttling" a user's bandwidth when a pre-set usage cap is exceeded, what is throttled is access to the network itself.

CVs and Jobs via Souktel

A non-profit group in the occupied West Bank has started a scheme that uses mobile phone text messaging to help young Palestinians find work.

The group, based in Ramallah, has already registered 8,000 Palestinians on its Souktel system, most of them recent graduates. The system connects them to about 150 leading employers who are looking for staff.

Internet access in the West Bank remains low, reaching about one-third of the population. Most computer use is at internet cafes, which are largely male-dominated domains in what is still a conservative society.

Souktel enables young people looking for work to register by answering a series of simple questions in Arabic through text messages, which are used to create a mini-CV. They then receive regular information about relevant jobs on offer.

It costs little to use apart from a slight premium charged on each text sent. In the same way, employers can post notices about job vacancies and filter applications.

The project comes at a time when despite forecasts of improved economic growth in the West Bank, unemployment still stands at around 20%, with that figure even higher among young people.

The Palestinians are a highly educated population but the Israeli occupation in the West Bank, with checkpoints, roadblocks and frequent restrictions, makes it costly and difficult to travel and do business. Universities rarely offer careers advice.

You don't need an iPhone or to download software. It's just messaging and it works on a phone from 1995.

Souktel, an SMS service based in the Middle East and East Africa, is all about connections. The service, launched in 2006, uses SMS to connect users to everything from jobs and internships to humanitarian aid and youth leadership programs.

The name comes from "souk," the Arabic word for "marketplace," and "tel," or "telephone. Although at least 80 percent of people in Palestine have access to mobile phones, most people have Internet access only in cafés or public places, said Jacob Korenblum, co-founder of Souktel. "Getting information about medical care, jobs, and food bank services can be difficult," he said. And even at Internet cafes, Korenblum said that many people, especially women, lack access to these services. "We wanted to develop a very simple service," he said. "That's how Souktel started."

Korenblum who is Canadian, said that although he has been working in the aid sector since 2000, his personal interest in Palestine began in 2005. "I came to the West Bank to work for an NGO. The main things I realized was that there wasn't so much a lack of aid, but rather a lack of good ways to find out about it." Currently, Souktel is run by a team of six people, four of whom are Palestinian.

Souktel is a combination of two services -- JobMatch and AidLink. JobMatch is an SMS service that connects people seeking jobs with employers. Job seekers can register via SMS with Souktel, and then, through a series of text messages, enter details about themselves into the system. These include location, skills, career interests, and level of education. Whenever the job seeker is looking for a job, he/she can text "match me" to Souktel to receive an instant list of jobs that matches the resume that is already stored in the Souktel system. The job listings include phone numbers so that the job seeker can call potential employers to set up an interview.

Korenblum said that at least 2,000 people use the service each month and the service has about 8,000 total users. In the past year, JobMatch has connected about 500 people with jobs. Users tend to be between the ages of 18 and 25, and the system recently expanded to include internships and volunteer opportunities. In June, about 170 people found jobs using Souktel, but the service’s success is partially reliant on the economy.

Earlier this year, Souktel launched services in the Iraq and Somaliland. In the future, Korenblum hopes that Souktel continues to grow, and could be used to connect people not only with jobs, but with educational programs or health and social services. "SMS is pervasive,” he said. “It is also by far the most cost-effective way for people to get the information they need." He also hopes to continue to share Souktel’s platform. “We've been struggling with it for three years now, and we've arrived at something that works,” he said. “We want to save someone else time in trying to develop it, so they have something that is useful for them.”

If you find this interesting, check out a Souktel presentation here.

SMS for Emergency Services

I blogged few months back about SMS for emergency services in USA now the same is being tried in UK.

Ofcom is trialling a new system to let deaf people access 999 services using text messaging.

The system lets users who can’t speak send a text message to emergency services. Their text is received by 999 assistants and read out to fire, police or other emergency service. A reply is also sent back via SMS.

The trial kicked off earlier this month, with Ofcom asking people to register to test the service. As the trial will use actual emergency messages, it needs enough people to register to get a good feel for how the system is working as most won’t actually have cause to use it.

To register, text “register” to 999; anyone not registered will not be able to use the service.
Ofcom noted that users shouldn’t assume their message has been received until they’ve received a reply, and that anyone sending hoax messages will be prosecuted.

If the trial goes well, the texting system could be in place as early as next year, Ofcom said. It’s being supported by the major telecoms companies, as well as emergency services and the Royal National Institute for Deaf People (RNID).

SMS to the emergency website here.

HSPA Functions and Benefits

Very interesting diagram summarising HSPA Functions and Benefits

Source: 3G Americas Whitepaper, HSPA to LTE-Advanced: 3GPP Broadband Evolution to IMT-Advanced (4G)

Network Interfaces for Applications using Parlay and OneAPI

Here is an old posting on Parlay/OSA that might be useful to put things in context.

An important development related to service evolution is operators making interfaces available to external applications for information and control. Two widely deployed capabilities today include location queries and short message service. With location, mobile devices or external applications (e.g., applications operating on computers outside of the network) can query the location of a user, subject to privacy restrictions. This can significantly enhance many applications including navigation, supplying location of nearby destinations (e.g., restaurants, stores), location of friends for social networking, and worker dispatch. With SMS, external applications can send user requested content such as flight updates.

Until now, the interfaces for such functions have either been proprietary, or specific to that function. However, there are now interfaces that span multiple functions using a consistent set of programming methods. One set is the Parlay X Web Services, a set of functions specified through a joint project of the Parlay Group, the European Telecommunications Standards Institute (ETSI) and 3GPP. The Open Mobile Alliance (OMA) now manages the Parlay X specifications. Parlay X Web Services include support for location and SMS, as well as many other functions with which developers will be able to build innovative applications.

Table 4 (above) summarizes the available Parlay X specifications. Operators are beginning to selectively deploy these functions. The advantage of this approach is that developers can build applications that are compatible with multiple operator networks.

A related project is GSMA OneAPI, a GSM Association project to also define network interfaces, but that prioritizes implementation based on expected market demand. OneAPI defines a simplified Web service for most functions that is essentially a subset of the related Parlay X Web service. It also defines a REST (Representational State Transfer) interface for most functions as an alternative to using the Web service. RESTful interfaces are simpler for developers to work with and experiment with than Web services.

Regardless of whether operators deploy with Parlay X or OneAPI, these are mainstream interfaces that will open wireless networks to thousands of Internet programmers who will be able to build applications that leverage the latent information and capabilities of wireless networks.

Source: 3G Americas Whitepaper '3GPP Broadband Evolution to IMT-Advanced (4G)'

Wireless Subscribers Forecast 2014

Source: Informa Telecoms & Media, WCIS+, June 2009

Via: 3G Americas Whitepaper, HSPA to LTE-Advanced: 3GPP Broadband Evolution to IMT-Advanced (4G)

Opera Mini: Better and More Popular

Opera Mini has been downloaded more than 25 million times from the GetJar mobile application store, the companies said.

The mobile browser is one of the most popular in the world because it is available on a variety of devices including Java, Android, BlackBerry, Windows Mobile, and other handsets. It is also able to run on relatively low-end hardware because it uses server-side compression technology to minimize the processing and bandwidth requirements.

Opera is bringing multipage browsing to its popular Mini browser, with a beta rolling out today. Mini 5.0 also gets a slick visual makeover, and touch support on devices that accept touch input.

Underneath it's the familiar Opera 4 Mini engine with a few tweaks, and existing users will be relieved that key shortcuts have been retained. But the proliferating screens of settings, bookmarks etc are now accessible by a pulldown menu. The address bar and search bar are integrated into the page view, almost exactly in the manner of iPhone Safari. Usually the ideas in the browser flow the other way.

Opera Mini 5, out now in beta, features a sleek new design to give the browser a more intuitive look and feel, the firm said. Also included is tabbed browsing, enabling users to browse several sites simultaneously, and support for touch screen as well as keypad-based browsing.

A Password Manager function acts as a "virtual memory bank" to store all a user's passwords for email, social networking and other online accounts, according to Opera.

Finally, Opera Mini 5 features Speed Dial, providing users with pre-selected web sites on loading the browser to jump straight to the content they want.

"The idea of navigating the vastness of the web from such a small screen can be a daunting leap, which is why we have long committed to make the browsing experience you are familiar with from your PC, easy to do on your mobile phone," said Jon von Tetzchner, chief executive of Opera Software.

"With new sleek navigation buttons, tabbed browsing and Speed Dial bookmarks, you are never more than a click away from where you want to go on the web."

TD-SCDMA, TDD and FDD

After my posting on TD-SCDMA so many people asked me about what TD-SCDMA is. I am surprised that so many people are not aware of TD-SCDMA. So here is a quick posting on that.

TDD and FDD Mode of Operation

Basically most of the UMTS networks in operation are Frequency Division Duplex (FDD) based. There is also another variant called the Time Division Duplex or TDD. In reality there is more than one variant of TDD, so the normal 5MHz bandwidth TDD is called Wideband TDD of WTDD. There is also another name for WTDD to confuse people, called the High Chip Rate TDD (HCR-TDD). There is another variant of TDD as would have guessed known as the Narrowband TDD (NTDD). NTDD is also known as Low Chip Rate TDD (LCR-TDD) and most popularly its known as TD-SCDMA or Time Division Synchronous CDMA.

"Synchronous" implies that uplink signals are synchronized at the base station receiver, achieved by continuous timing adjustments. This reduces the interference between users of the same timeslot using different codes by improving the orthogonality between the codes, therefore increasing system capacity, at the cost of some hardware complexity in achieving uplink synchronization.

The normal bandwidth of FDD or TDD mode of operation is 5 MHz. This gives a chip rate of 3.84 Mcps (Mega chips per second). The corresponding figure for TD-SCDMA is 1.66 Mhz and 1.28 Mcps.

Assymetric operation in TDD mode

The advantage of TDD over FDD are:

• Does not require paired spectrum because FDD uses different frequencies for UL and DL whereas TDD uses the same frequency hence its more easy to deploy
• Channel charachteristics is the same in both directions due to same band
• You can dynamically change the UL and the DL bandwidth allocation depending on the traffic.
  

The dis-advantage of TDD over FDD are:

• Switching between transmission directions requires time, and the switching transients must be controlled. To avoid corrupted transmission, the uplink and downlink transmissions require a common means of agreeing on transmission direction and allowed time to transmit. Corruption of transmission is avoided by allocating a guard period which allows uncorrupted propagation to counter the propagation delay. Discontinuous transmission may also cause audible interference to audio equipment that does not comply with electromagnetic susceptibility requirements.
• Base stations need to be synchronised with respect to the uplink and downlink transmission times. If neighbouring base stations use different uplink and downlink assignments and share the same channel, then interference may occur between cells. This can increase the complexity of the system and the cost.
• Also it does not support soft/softer handovers

Timing Synchronisation between different terminals

By the way, in Release 7 a new TDD mode of operation with 10 MHz bandwidth (7.86 Mcps) has been added. Unfortunately I dont know much about it.

You can read more about TD-SCDMA in whitepaper 'TD-SCDMA: the Solution for TDD bands'

You can find more information on TD-SCDMA at: http://www.td-forum.org/en/

Scratch Input: Future Input for Mobile Phones

Very interesting...not being able to see past your fingers on smaller devices. That's where "scratch input" comes in. Harrison's prototype uses a digital stethoscope to pick up the sound of scratching on a table or wall. The device attached to the stethoscope, be it a phone, watch or a computer, is programmed to recognise the sounds of different scratch gestures. By tracing a spiral on his desk, Harrison can, for example, turn the volume down on his media player. Ultimately the microphone would be built into the device. Imagine a touch screen watchphone that can be controlled simply by scratching your arm.

You may be interested in reading this article Touch Screens at The Independent here.

Ericsson's Exciter: Conceptual mobile Personal Area Mediator (PAM)

Interesting Video:



If you find this interesting, there is a presentation you can look at here. Unfortunately its in swedish but you can get an idea about which direction things will be going in future.

Huawei becomes a big player in LTE

[Shenzhen, China, 1 September 2009] Huawei, a leader in providing next-generation telecommunications network solutions for operators around the world, today announced that it has been granted 147 Long Term Evolution (LTE) patents by the European Telecommunications Standards Institute (ETSI), representing 12 percent of the total existing 1,272 LTE patents assigned by ETSI as of August 2009. The patents granted were across several key LTE sub-sectors, such as physical-layer air interface, radio resource management and connection management.

Huawei’s robust investment in LTE research and development has accelerated the commercialization of LTE technology. In June 2009, Huawei connected the world’s first LTE mobile broadband internet connection for Teliasonera in Oslo, Norway.

Huawei is an active participant in 91 standardization organizations, with over 100 committee leadership positions. In 2008, Huawei had filed a total of 35,773 patent applications globally.

Last year LG had claimed that it has upto 300 patents, not sure if that is still true.

New report on Mobile Broadband Evolution from HSPA to LTE-Advanced

The white paper, HSPA to LTE-Advanced: 3GPP Broadband Evolution to IMT-Advanced (4G), discusses the 3GPP evolution of EDGE, HSPA and LTE, their capabilities and their positions relative to other primary competing technologies and how these technologies fit into the ITU roadmap that leads to IMT-Advanced.

The following are some of the important observations and conclusions of the report:

• HSPA Evolution (HSPA+) provides a strategic performance roadmap advantage for GSM-HSPA operators. Features such as dual-carrier operation, MIMO and higher-order modulation offer operators multiple options for improving their networks, and some of these features are simply network software upgrades.
• Persistent innovation in developing HSPA and HSPA+ is bringing UMTS to its full potential providing mobile broadband to the mass market; in current deployments, HSPA users regularly experience throughput rates well in excess of 1 Mbps under favorable conditions, on both downlinks and uplinks, with 4 Mbps downlink speed commonly being measured. Planned enhancements such as dual-carrier operation will double peak user-achievable throughput rates.
• LTE has become the next-generation platform of choice for GSM-HSPA and CDMA/EV-DO operators.
• The 3GPP OFDMA approach used in LTE matches or exceeds the capabilities of any other OFDMA system providing the most powerful wide area wireless technology ever developed. Peak theoretical downlink rates are 326 Mbps in a 20 MHz channel bandwidth.
• 3GPP has made significant progress investigating how to enhance LTE to meet the requirements of IMT-Advanced in a project called LTE-Advanced.

With a customer base of 4 billion connections today, the GSM family of technologies is available on nearly 800 networks in 219 countries worldwide. Building on this base, UMTS-HSPA – the world’s dominant mobile broadband technology today – has proven to be the most widely deployed and adopted 3G technology of all time, with more than 352 operators in various stages of deployment, including 277 commercial HSPA networks in 116 countries.

The white paper explains the tremendous opportunity afforded to GSM-HSPA operators via the 3GPP roadmap to HSPA+. While OFDMA systems such as LTE and WiMAX have attracted a great amount of attention, evolving HSPA to exploit available radio technologies can significantly enhance its performance capabilities and extend the life of sizable operator HSPA infrastructure investments. Techniques include advanced receivers, MIMO, Continuous Packet Connectivity, Higher-Order Modulation and One Tunnel Architecture, many of which are included in the standardization of 3GPP Release 7 and Release 8.

Depending on the features implemented, HSPA+ can exceed the capabilities of IEEE 802.16e-2005 (Mobile WiMAX Release-1) in the same amount of spectrum. Beyond the peak data rate of 42 Mbps for HSPA+ in Release 8 (with 2X2 MIMO, DL 64 QAM and UL 16 QAM), Release 9 may specify 2X2 MIMO in combination with dual-carrier operation, which would further boost peak theoretical downlink network rates to 84 Mbps. In addition to the increased speeds, HSPA+ also will more than double HSPA capacity and has the potential of reducing latency to below 25 milliseconds.

HSPA and HSPA+ will continue to dominate mobile broadband subscriptions worldwide for the remainder of this decade and well into the next. However, announcements have already begun in support of the next 3GPP evolutionary step, LTE. Trials and deployments of LTE will begin in 2010 by leading operators including AT&T, China Mobile, China Telecom, NTT DoCoMo, Verizon and Vodafone. In fact, today there are more than 2 billion subscriptions represented by combining the total existing customer bases of the more than 100 operators, both GSM and CDMA operators, who have announced indications of their intention to deploy LTE networks.

The deployment of LTE and its coexistence with UMTS-HSPA will be analogous to the deployment of UMTS-HSPA and its coexistence with GSM-EDGE.

Whitepaper available to download here.
Accompanying slide presentation available here.

HSPA+ is everywhere...

EMobile Ltd. , Japan's smallest mobile operator, has deployed HSPA+, also known as HSPA Evolved, in the country's major cities, including Tokyo, Osaka, Yokohama, and Nagoya.

This deployment is based on equipment from Ericsson AB, which supplied the core network and core systems integration services as well as the majority of the radio access network. It builds out the geographical coverage for HSPA+ that EMobile has already established using Huawei Technologies Co. Ltd. equipment in a number of Japan's other cities, including Hokkaido, Sendai, Niigata, Hiroshima, Fukuoka, and Nagasaki.

Japan is a market with a reputation for being first with new technology, but HSPA+ has been passed over, most notably by market leader NTT DoCoMo Inc., which has focused on moving to Long-Term Evolution (LTE) as fast as possible.

The No. 2 player, KDDI Corp. , is similarly pushing toward LTE, although from a CDMA base that takes HSPA out of the equation, while Softbank Mobile Corp. is known to have run HSPA+ lab trials and has also said it will move to LTE when it gets the necessary spectrum.

EMobile is by far the smallest of Japan's operators, with just 1.67 million subscribers at the end of the second quarter, compared to DoCoMo's 54.86 million, KDDI's 31 million, and Softbank's 20.96 million customers, according to Wireless Intelligence .

You can check out the HSPA+ features in Rel-7 and Rel-8 here.

Zapp, mobile operator of Romania, has launched the first stage of its HSPA+, the upgraded mobile broadband service in the capital city of Bucharest. With this service, the subscribers can enjoy peak download speeds of 21.6Mbps, while upload speeds will increase by up to 15 times, from 384Kbps to 5.8Mbps. According to a report, Zapp contracted Chinese firm ZTE to deploy the network, which will run parallel to the cellco’s second phase 3G rollout, expanding its UMTS services to 63 cities nationwide.


O2 Germany is currently running a friendly user test in Munich where O2 Germany's technology partner is Huawei. Beside being O2's network partner for the overall HSPA-network upgrade, Huawei is also O2 Germany's major vendor for UMTS sticks and therefore O2 Germany is using Huawei equipment for the HSPA+ test as well. The used Huawei E182E stick is a slide-out USB stick, supporting quadband GSM/GPRS/EDGE as well as quadband UMTS/HSDPA up to 21.6 Mbps and HSUPA up to 5.76 Mbps. Furthermore the stick is MIMO ready.

Spanish mobile network operator Vodafone Spain has announced it will begin deploying HSPA+ technology across its network in the autumn of 2009. The cellco says the upgrade will allow its infrastructure to achieve theoretical download speeds of up to 21.6Mbps, while uplink speeds would increase to up to 5.7Mbps. Initially Vodafone expects to launch the increased speeds in seven unnamed ‘major’ cities, with further expansion to follow. In addition, Francisco Roman, president and CEO of Vodafone Spain, has announced that the operator plans to further extend its provision of ADSL services across the country, although it has not given any specifics for areas it plans to extend its reach to.

­Swiss network operator, Swisscom says that it is deploying a HSPA+ (HSPA Evolution) upgrade, with the first areas completed in time for the ITU Telecom World 2009 in Geneva. The upgrade will offer a peak rate data transfer rate of 28.8 Mbps - although the more realistic average is no higher than 8Mbps. The network has launched a HSPA 14.4Mbps service at the beginning of this year.

Chunghwa Telecom, the Taiwanese mobile operator has reportedly selected Nokia Siemens Networks (NSN) to upgrade its wireless infrastructure with HSPA+ technology. The operator intends to launch its HSPA+ and 3G services by 2010, boosting mobile broadband download speeds to up to 21Mbps. Initially, devices able to utilise the HSPA+ service will include data network cards, USB dongles and wireless modules before it is extended to cover smartphones, netbooks and notebooks.

ZTE Corp has completed the interoperability test (IOT) of its 3GPP R7-based HSPA+ MIMO (multiple-input multiple-output) solution, conducted in conjunction with mainstream terminal chip platform manufacturers, in July 2009.

The MIMO solution, realized with its SDR-based next-generation base station, has reached a theoretical speed limit of 28.8Mbps in both cable connection and wireless environment tests. The trials included data download services for UDP (User Datagram Protocol) and FTP (File Transfer Protocol), as well as various IOT item tests.

All the test results indicated stable and fast data download performance. The successful IOT testing confirms that ZTE's MIMO solution is now ready for large-scale commercial deployment worldwide.

Improved LTE backhaul via Alcatel-Lucent's 10G GPON

“The PON vendor landscape got interesting in the fourth quarter of 2008, with Alcatel-Lucent, Motorola, and Tellabs each grabbing 10% of worldwide revenue share, behind perennial leader Mitsubishi and the now number-two player, Fiberhome. In the fast-growing GPON segment, front-runner Alcatel-Lucent is being seriously challenged by Motorola, which increased its quarterly GPON revenue share 5 points in 4Q08. Meanwhile, the EPON segment, long dominated by Mitsubishi and Hitachi, is seeing some action as Sumitomo, Fiberhome, and Dasan Networks all moved up.” - Jeff Heynen, Directing Analyst, Broadband and Video, Infonetics Research

I have blogged a bit about GPON and Backhaul before. Click on the links if you havent seen the posts before.

During this year's Broadband World Forum Europe, Alcatel-Lucent not only shows that it masters next-generation wireline and wireless access. The company also highlights that Long Term Evolution (LTE) and next-generation passive optical networking (PON) technologies converge seamlessly for a smooth delivery of the most demanding, high-speed broadband services.

The live demonstration in Alcatel-Lucent's Paris demo center shows LTE's capability to deal with multiple concurrent video streams and fast channel change - and is complemented by a high-capacity 10G GPON backhaul solution for future-safe backhaul via fiber.

Alcatel-Lucent is at the forefront of developing cutting-edge technologies long before they are standardized. Even though the 10G GPON standards are still being ratified, Alcatel-Lucent shows it is ready - when needed - to meet the request for higher capacities in its customers' access networks.

Alcatel-Lucent is engaged in over 95 FTTH projects around the world, over 80 of which are with GPON (as-of Q2, 2009). In Gartner's latest FTTH Magic Quadrant assessment, Alcatel-Lucent was positioned in the leaders quadrant for the fiber-to-the-home space.

Alcatel-Lucent is also opening up details of its optical management and control interfaces (OMCIs) in a bid to help create a true multi-vendor gigabit passive optical networking (GPON) infrastructure.

Announced at this year's Broadband World Forum Europe in Paris, the first version of the OMCI Interoperability Implementer's Guide is aimed at helping other optical network terminal vendors integrate their hardware with Alcatel-Lucent's.

TD-SCDMA: Where are we

Interesting things are going on in the Chinese market.

A new mobile phone platform has been launched by China Mobile for it's TD-SCDMA 3G mobile phone network. In fact, it’s the first ever mobile phone operating system designed by a 3G mobile phone operator and is called Ophone. The OPhone is a linux-based terminal software platform for mobile internet.

In conjunction with the announcement for the Ophone, China Mobile announced a number of Ophone compatible handsets from Samsung, Lenovo, Phillips and Dell.

China Mobile stated that by introducing the Ophone operating system, significant savings will be made on TD-SCDMA handset design and development.

"Dopod CEO Dennis Chen said the Qilin handset is the first result of China Mobile's $7 million in subsidies to encourage TD-SCDMA handset development. Dopod has expanded investment in manpower and funding towards TD-SCDMA R&D and will release numerous high-end TD-SDCMA (sic) handsets next year."

The HTC Qilin has some pretty good genes: WM 6.5, 600MHz TI OMAP processor, 3.6" WVGA screen, GPS, 5MP camera, and CMMB Mobile TV and is apparently based on HTC's Whitestone design. The TD-SCDMA standard is China's home-grown 3G standard, which means that the Qilin won't have access to 3G networks outside of China. Having said that, HTC and China Mobile have just signed an MOU to partner up in R&D, market research, and product development, so the Qilin will be just the first in a series of handsets HTC will develop for China Mobile.

The Qilin is slated for release in December, which puts it just in time for runup to the Chinese New Year holidays.



China Mobile and LG have recently showcased the GW880, LG’s first smartphone to use the Android-based OMS (Open Mobile System) platform.

Featuring GSM and TD-SCDMA connectivity, the LG GW880 will be available via the largest Chinese mobile carrier later this year, for a price that was not announced.

The smartphone is a high-end one, as it comes with a 3.5 inch WVGA touchscreen display, 5MP camera with flash, Mobile TV, 512MB ROM and 256MB RAM.

We’re probably not going to see the LG GW880 outside China, but that’s OK, since LG is surely preparing some Android phones for other markets.

China Mobile saw its number of TD-SCDMA subscribers increase by 129,000 to 1.088 million in July. The first batch of handsets were released in May.

Nearly one half billion people subscribed to China Mobile cellular services last month, but the giant's efforts to promote a Chinese 3G standard have made little headway. The world's largest carrier grew to 498 million mobile subscribers last month, a number larger than the populations of the U.S. or the European Union. The number of subscribers using their mobile phones to play games, download music and surf the Internet also rose during the first half of the year, China Mobile said Thursday. But growth was slow for TD-SCDMA, a domestic 3G mobile standard that the government tapped China Mobile to market. Subscribers surpassed 1 million in July, continuing a slow climb upward from the launch of TD-SCDMA services in January.

China Mobile Communications Corp. aims to have as many as 80 million users of its homegrown third-generation mobile technology within two years of its initial rollout, Minister of Industry and Information Technology Li Yizhong said. Speaking at a news briefing, Li acknowledged the domestic standard isn't as developed as its more mature international rivals, but said he is confident in its commercial development.

Youtube Clip on Dangers of driving while texting

The film tells the story of a fictional 17-year-old girl, Cassie Cowan (nickname COW), who is distracted by her mobile for a few seconds while driving with two friends.

COW – a "nice girl from a nice valleys family" – causes a devastating crash which kills her friends and another couple. The impact and its aftermath is portrayed in vivid, harrowing and bloody detail.

One girl's face hits the windscreen with sickening force. A child in the car COW crashes into asks: "When will mummy and daddy wake up?" while a baby strapped into a child seat stares unblinking and may be dead.

Actually, police had intended to commission a different film – on joyriding. But when they spoke to pupils at Tredegar comprehensive, the youngsters told them that texting while driving was a much more important issue for them.

With a budget of £10,000, film-maker Peter Watkins-Hughes was asked to write and direct the film. Local people donated props including the cars that are smashed up and the locations while Watkins-Hughes and his cast gave their time.

A 30-minute version of the film is due to be shown for the first time this autumn but Watkins-Hughes put a four-minute clip of it on YouTube (entitled COW test 001) to show it to a friend. For weeks the clip remained unnoticed by anyone but the friend and a few crew members.

Then suddenly it began to attract hits. It was copied on to other sites, attracted attention around the world and within a couple of weeks became one of the most popular viral videos. Today it was still ninth on one global viral video chart. Clips about Oasis and Jay-Z were at first and second place.

Watkins-Hughes said it felt like being in an Ealing comedy when a small Welsh community had suddenly attracted worldwide attention.

The "weirdest" moment for him was when his explanation, "We've gone for grim reality", was a quote of the day on the Time website.

Watkins-Hughes said he thought it was so powerful because the violence of the crash was shown but the film then "lingered" on the human price – the baby, the child asking about his mother and father. And the screams of COW, who survives the crash.

The film has struck such a chord in the US where the danger of texting while driving is a big issue because it is not illegal in all states. The trend in America has been to try to get the anti-texting message across more gently through humour or playing on the emotions but not showing violence.

However, one survey in the US found that 80% of people who had seen the Gwent film were less likely to text while driving than before.

In the UK, the road safety charity Brake, having been asked to watch the clip by the Guardian, praised the film-makers and said it was important to show the reality of road crashes.

Farmers worldwide being helped by Mobile Phones Technology

Airtel has entered into a strategic tie-up with IFFCO (Indian Farmers Fertilisers Cooperative) for providing agriculture and allied information to farmers through mobile phones. The facility was formally launched by the Chief Operating Officer (Andhra Pradesh) of Bharti Airtel Limited, Rajnish Kaul, at a function at Anakapalle town, about 40 km from here on Tuesday.

Addressing a media conference on the occasion, he said that the unique facility would benefit over 10 lakh IFFCO society members of rural Andhra Pradesh by giving them access to vital information. The farmer members would be given five free voice messages on farming techniques, weather forecasts, dairy farming, animal husbandry, fertilizer availability and rural health initiatives.

Mr. Kaul said the farmers could also call a dedicated free helpline to get answers from a qualified veterinarian to their specific queries regarding the health of their animals. He said that SIM cards would be provided at subsidised rates and lifetime activation would be done for a mere Rs.47. Calls between the members would be charged at 50 paise a minute. The SIMs would be compatible with any mobile handsets and farmers could buy the handsets of their choice depending on their purchasing power. He said the facility was launched about six months ago in various districts of the State and there were already 65,000 connections.

Question Box provides a service in India and Uganda. In India, phone boxes are installed in slums and villages that connect users to operators that will answer questions. In Uganda, users can call in from any mobile phone and ask their questions. The operators have access to a repository of previously asked questions (and their answers), and they can also occasionally consult the Internet. A special search engine and database were also built specifically for the project.

Another initiative, Avaaj Otalo, provides an audio community forum for farmers in rural Gujarat, India. Working with an organization that produced a popular radio program, Otalo provides a call-in number where farmers can exchange questions and answers. Users are also able to listen to archives of the radio program.

These projects differ in that Question Box avoids having to process users' questions by adding a human listener in the loop; Avaaj Otalo avoids processing by organizing their collection of audio prompts with into a menu. Both programs, however, have yet to deal with the problem of cost because they subsidize the service for users. Otalo operates with a toll-free number and Question Box provides the phones to call from in India. In Uganda, Grameen Community Knowledge Workers provides the mobile phones.

It's easy to see why the fishermen of the southern Indian state of Kerala captured the attention of a Harvard economist when they began using mobile phones a few years ago to track prices in the markets where they sold their catch of the day. Observing how these devices can be used to promote economic growth, Robert Jensen wrote in a 2007 paper titled, "The Visible Hand(set): Mobile Phones and Market Performance in South Indian Fisheries -- The Micro and Mackerel Economics of Information," that "before mobile phones, deciding which [market] would offer the best price was sheer guesswork." With mobile phones, however, suddenly it became an information-based decision. What's more, noted Jensen (who is currently at Brown University in Rhode Island), "it's not a zero-sum trade-off." The fishermen's customers benefitted from lower prices and greater choice, and there was less waste since the fishermen could easily identify the villages that would have the greatest demand for their fish each day.

Now Jensen's "visible handset" is reaching further into rural India. Following a nationwide launch this summer of Nokia Life Tools (NLT), India's farmers can use their mobile phones to access tailored information to help them grow, harvest and sell their crops and manage their livestock. "There is no reason why farmers should not be as successful as fishermen," says Ravi Bapna, associate professor of information systems at the Carlson School of Management in Minnesota and executive director of the Centre for Information Technology and the Networked Economy at Hyderabad-based Indian School of Business (ISB).

Consider Ravindra Shinde, a farmer in Magardhokada, a village in the Nagpur district of Maharashtra. When he recently harvested 125 quintal (a quintal is 100 kilograms) of soybeans and was about to take the crop to market, the price was $32 a quintal. But then he received a message on his handset that soybean production in the U.S. and Argentina had fallen, so he held back and later sold his crop for $48 a quintal.

IN the early 1990s, I was engaged in an empirical research work relating to the nexus between mobile phone and poverty in rural Bangladesh. However, friends used to tease me and raise their eyebrows on hearing about the project and my interest at that time. This was to be expected in the early 1990s when, not to speak of the poor, even the "solvent" could not afford to have a mobile set. It was treated as a "luxury" item, only to be monopolised by the moneyed people.

My research findings on village pay phones of the Grameen Bank at that time -- and as published in international journals in subsequent years -- clearly showed that mobile phones could help the poor escape "rural penalty" (a la H. Hudson), defined as poverty mainly due to distance, poor connectivity and asymmetric information. However, as of today, about 40 percent of the rural households in Bangladesh are reported to have access to mobile phones and roughly one-fourth of the users are poor. Rickshaw pullers, fishermen, traders all use it to minimise information asymmetry and quicken communication between two points.

About a decade later, I was invited to comment on two research papers showing the impacts of mobile phones on farmers and traders in Africa.

The first paper was by Megumi Muto and Takashi Yamano, both representing JICA and Foundation for Advanced Studies on International Development (FASID). They drew upon panel data of rural Uganda where banana producers could reduce marketing costs and raise income with expansion of mobile phone coverage. The message is that the expansion of mobile networks increased market participation and sales of the perishable product, banana. More importantly, small producers and farmers in remote areas gained the most.

As information flow increases due to the expanded mobile phone coverage, the cost of crop marketing is expected to decrease, particularly in remote areas where potential marketing gains from the increased information flow is large. We indeed find that the network expansion has a larger impact in market participation in areas farther away from the district centers than in closer areas.

The second paper was presented by Jenny C. Aker of the University of California, Berkeley, on the impact of mobile phones on price dispersion of grains in Niger. Using a sequential searching model, the researcher observed that cell phones increased traders' reservation sales price and the number of markets over which they searched. This reduces price dispersion across markets. To be specific, grain price dispersion reduced by 6-7 percent and reduced intra-annual price variation by 10 percent.

What is important, and as revealed in both papers, is that every farmer need not possess a set. It could be the community, producers' organisations and others from where the price information could spread, either as a "public good" or as a "private good." A participant from the audience in that seminar informed us that in his village in Africa, a mobile phone is hung from the branch of a tree and interested persons could use it on payment of a fee. Second, even with access to mobile phones, full gains might not be reaped as farmers might need more information. The role of public authority and media in this respect is very important. Again, producers' organisations could form an information forum of their own to be more effective at bargaining than individual initiatives.

LTE Buzz from Alcatel Lucent

Alcatel-Lucent has produced a LTE Widget that provides real-time LTE news and information direct on your PC. Very useful if you want to keep a watch on breaking news and information. The widget can be downloaded from their website here.

Samsung claims First commercial LTE Modem development

Samsung Electronics Co. Ltd., announced that it has developed the first Long Term Evolution (LTE) modem that complies with the latest standards of the 3rd Generation Partnership Project (3GPP), which were released in March 2009. Utilizing Release 8 of the 3GPP, this LTE modem is a significant upgrade from the previous standard that was released in December 2008.

The modem, branded the Kalmia, supports download speed up to 100Mbps and upload speed of 50Mbps within the 20MHz frequency bandwidth. Users of a mobile device equipped with the LTE chipset can download a high-definition movie file (800MB) in one minute at speeds of 100Mbps, while simultaneously streaming four high-definition movies with no buffering.

Samsung also announced it has successfully developed a 3G baseband modem based on the Release 7 standard with an HSPA (High Speed Packet Access) Evolution platform.

This modem, branded the Broom, allows download speeds of up to 28Mbps and upload speeds of 11.5 Mbps. This makes the Release 7 more than twice as fast as the Release 6 HSPA Service, which had a maximum download speed of 14.4Mbps.

Separately, Samsung Electronics has also developed the mobile WiMAX (IEEE 802.16e) modem chip, a product that is already resonating in the mobile market. The company has already adopted the modem into commercial WiBro handsets in Korea. With this new modem, Samsung has delivered WiMAX and LTE model solutions, which are the two major wireless mobile communications systems for the next generation. The company has also demonstrated a full lineup of modems from 2G/3G to modems for the next generation of mobile telecommunication systems with its HSDPA Evolution modems.

Samsung is also strengthening its position as a leader in mobile telecommunication system standards. Samsung currently holds the most chairman seats within the IEEE 802.16 Working Group, a WiMAX standardization association, and also chairs the WiMAX Forum, an affiliate organization. Additionally, Samsung is highly influential in securing many leading positions in other organizations such as the Technology Working Group.

At 3GPP, an association that specifies standards for LTE, Samsung ranks in the top group according to its number of contributions and has four seats in the wireless networking standardization working group executive board. Samsung has also served as the chair for two years in the steering committee of LSTI (LTE/SAE Trial Initiative), an organization that works closely with LTE. The company is also actively participating in various programs for NGMN (Next Generation Mobile Networks), a business association of global and leading mobile operators.

LTE NAS and AS states and their relation

Continuing from where we left yesterday.


As you can see that there are three different states in an LTE system we are talking about.

The first is the RRC state that goes from RRC_IDLE to RRC_CONNECTED everytime the UE needs to be connected to the eNodeB.

Once the UE is RRC_CONNECTED, it can register with the Mobility Management Entity (MME), and the EPS Mobility Management (EMM) state moves from EMM-DEREGISTERED to EMM-REGISTERED

The EPS Connection Management (ECM) state (ECM-IDLE or ECM-CONNECTED) reflects the connectivity of the UE with the Evolved Packet Core (EPC). See the Interface diagram for details.

The NAS states, and their relationship to the AS RRC states can be seen in the diagram above

I have picked up some information from: LTE: The UMTS Long Term Evolution: From Theory to Practice

LTE Protocol Stack

Over the weekend, I was looking in the standards for an LTE Protocol stack and none of the diagrams seemed simple enough so I made one myself.
I also found a very detailed one on Nomor Research site.

I was also looking for some details on EMM (EPS Mobility Management) and ECM (EPS Connection Management) and found couple of (expected ;) blogs that had the required information. If interested have a look here and here.