LTE World Summit - Day 3 Pics

Some Pics from day 3.

This is from my breakfast briefing session.

The above are Signallion Test UE. Check the 'SORBAS Test UE' flyer here.

Thats the Signalion's test engineer running some simulations ;)

Thats Manish Singh from Continuous Computing explaining about their LTE protocol solutions.

Qasara's LTE Protocol stack. See their presss release.

Everyone enjoying the break on the last day.

LTE World Summit: Day 2 roundup

I had been enjoying some delicious Thai food yesterday night and as a result didnt wake up on time for the Breakfast briefing. Adrian Scrase, the 3GPP VP started and managed the morning session. I have always enjoyed him speaking and chairing events as he is full of knowledge and quite practical about the technologies.

Hans Erik Karsten from Telenor, Norway, spoke asbout the Norway market and gave some interesting facts and figures. For example, 2% of users are using 40% of the capacity and these are the PC users. 10% of the users use 80% of the capacity. In fact one person downloaded 230GB of data in a month (flat pricing schemes ;). N95 users use 10 times the data of an average phone. From Telenor point of view, LTE is an evolutionary step. The main advantage of LTE is flexible spectrum usage. They are also exploring Femtocells and Self Organising Networks (SON) will be the key. There are many upgrade paths from GSM/UMTS to LTE but there is no single solution for all different markets. Sweden will rollout LTE asap in 2.6GHz and 900MHz in future. Norway will be 2nd.

Julius Robson from LSTI (and Nortel) spoke about Industry wide trials and IOT. LSTI have now done real world analysis rather than the peak rate analysis and there were lots of interesting facts and figures that I will dive in later.

There has been lots of mention of refarming of 900MHz band and 'Digital Dividend' band. It was mentioned couple of times in the Panel discussion as well. Deploying LTE in 1800 band is not favioured by some as it wont provide much advantage over the 2.6GHz band regarding the coverage. Nakamura-san from NTT DoCoMo mentioned that none of the operators in Europe use Tx-Diversity and it is possible that MIMO will be deployed selectively in higher bands initially. There is a new initiative in Femto forum to open up Femtocell API's to third party and we may see in future that these API's may be opened up on Macro cells as well. See this blog post I did earlier.

Paul Steinberg from Motorola discussed about the cost and capacity. Again lots of facts and figures that I will dive in later. Interesting fact mentioned was 75% of users watch online video. According to him, LTE satisfies capacity and decreases TCO (Total Cost of Ownership). One of the advantages of OFDM is that there is no cell breathing (unlike WCDMA), there is SON and spectral efficiency is 3-4x. He also mentioned about the green advancements that Motorola have achieved. They are able to show 8x reduction in power requirements. There was some discussion about the bands and they think the first bands to be used would be 2.6GHz followed by 800, 900, 700 (Digital dividend bands which are different in different parts)

Doug Wolff from Alcatel Lucent talked about the US market. He mentioned that Verizon and AT&T has 60% US coverage. I will have to go in detail on this one later.

Adrian Scrase talked about 3GPP release 8 features and mentioned about the other main non-LTE features in Rel-8 namely ETWS, eCall amd ICE. I have talked about ETWS here and ICE here. Will discuss eCall in a future post.

Stephen Hayes from Ericsson talked about Rel-9 features. There are lots of things I want to talk about but it will have to wait for another post. I have already mentioned some of Rel-9 features here but will have to update the list soon.

Takehiro Nakamura from NTT DoCoMo talked about Release-9 and LTE Advanced and about Relay features in LTE Advanced. This presentation will probably end up on my LTE-Advanced page.

Charles Brrokson who is ETSI Security chair spoke about security in LTE and Rel-8 and how its different from UMTS. Its too technical to be covered in this post.

Giovanni Romano from Telecom Italia in Italy talked about their strategy and plans in Italy. He mentioned that there are already 1409 HSPA form factors available and hence they plan to have atleast 80% coverage in Italy for HSPA first. Later they have to think about moving either to HSPA+ or to LTE. The move to LTE will also depend on if Spectrum decisions have been made and the status of LTE device test certification.

Finally, Eiko Seidel spoke about LTE-Advanced and Rel-10. Will have to wait for another post though.

LTE World Summit - Day 2 Pics

Here are few Pics that I took today.


The R&S CMW 500 is seen to be doing MIMO testing with LG UE. The throughput was reaching upto 60Mbps.

Thats the LG LTE UE being used by R&S.

Thats the Anritsu MD8430 LTE Network Simulator and MD8435 UE Simulator. They were showing throughputs of 100Mbps DL and around 45Mbps in UL. The RTD tool (I am going to cover that in a seperate blog in few weeks time) can be seen on top right.

Anritsu engineer working ;)

Tektronix simulators. Apparently they have a solution for everything from drive testing to Femtocell test equipment. Hopefully more later

I also went to Ericsson Demo/Roadshow for LTE, HSPA and IMS Technologies. Unfortunately they didnt allow anyone to take any photographs.

LTE World Summit - Day 1 roundup

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

LTE World Summit - Day 1 Pics

We had an interesting first day at the LTE World Summit in Berlin. There were no breaking news though. Summary coming in the next post after the Pics.

The lunch was sponsored by Starent Networks. Here is a Pic of their cake. Nice cake but I dont like chocolate cake. I would have preferred strawberry ;)

This above is Agilent's test mobile that can be used for drive testing.

Agilent has a massive and impressive presence here. I attended their workshop yesterday, will report the details later.

Ericsson are showing off the new TEMS that can be used for LTE drive testing, etc.

mimoOn are showing their Test Mobile and their complete solution for eNodeB, etc.

Very interesting to see LTE Test Mobiles from 3 companies already available.

Setcom is a new entrant (even though they have been present for long time but I never heard of them before) in Network Simulator area. They have plan to do Conformance tests for the LTE mobile. They claim to be ready already with basic test functionality. Till date the Conformance test market have been dominated by Anritsu, Agilent (Anite), Aeroflex and R&S. I have already heard of AT4 Wireless being active in this area for LTE. It would be interesting to see one more player.

In Berlin for LTE World Summit

Just a day in Berlin to look around is not enough, especially if you are a bit tired due to your journey. I managed to go round to few places though and Berlin does look like a place that need to be explored.

Here are some photographs from Berlin:

All the above photographs are from The ruins of the Kaiser Wilhelm Memorial Church in Berlin, destroyed by Allied bombing in Second World War and preserved as a memorial

The final pic is of the Berlin Aquarium. Maybe the next visit, I will go and check it out.

New LTE Patent Pool attempt

Via Licensing Corp. is looking to administer a patent pool for companies and research institutes claiming to have Intellectual Property for the emerging fast date rate cellular technology Long Term Evolution (LTE).

Last April a group of equipment vendors and handset makers already teamed up to craft a licensing framework for the fourth-generation mobile standard that is based on the 3G Partnership Project's (3GPP) E-UTRA Series 36, release 8 specifications.

The equipment vendors and handset makers that teamed up in April 2008 to establish rules for licensing patents related to the technology included Nokia, Nokia Siemens Networks, NextWave Wireless, Alcatel-Lucent, Sony Ericsson, NEC and Ericsson. They decided to push for "fair and reasonable" licensing terms for the patents related to the so-called 4G wireless network technology.

MPEG LA LLC (Denver, Colo.), the organization set up to administer access to MPEG patents, but which has also branched out into other sectors, has also started working on a patent pool for LTE and has said that several companies have already shown interest in participating in its pooling efforts.

MPEG LA, LLC recently announced that it has made significant progress working with a group of interested companies to facilitate creation of a joint patent pool license for the Long Term Evolution (LTE) Standard for mobile telecommunications. MPEG LA’s efforts, started last year, have been directed toward educating the market about the benefits of a pool license to address the patent thicket around this next generation wireless technology and assist the market with its adoption.

“The market is ready, and we are proud that industry leading companies have invited us to facilitate creation of an LTE pool license,” said MPEG LA President and CEO Larry Horn. “Given the history of telecommunications patent pools, MPEG LA has taken the time to consult directly with mobile network operators, network equipment manufacturers and mobile handset companies regarding the benefits of a patent pool for LTE, and they have encouraged MPEG LA to move forward with this effort. We are pleased by their vote of confidence. Next generation wireless technology, with its multifunctional capabilities, begs for a patent pool licensing alternative to make its full potential available to consumers worldwide, and MPEG LA’s success in creating large pool licenses uniquely positions us to achieve it.”

Via already administers patent pools for a number of technologies, notably in the broadcast, audio and wireless space, including those for MPEG2, 802.11 based Wi-Fi and near field communications (NFC). The company is a spin-out from Dolby Laboratories Inc.

Via can’t force patent holders to play, and without a majority of solid patents with which to negotiate, its attempts will fail. There’s little reason for a larger company to join a patent pool, unless it wants to help push through a standard, which isn’t the case with LTE.

Patent pools have become increasingly popular in recent years to handle licensing in cases of relatively large numbers of patent holders and licensors. The pools can help lower transaction costs and reduce uncertainty and time spent negotiating deals, sometimes with competitors across barriers of language and geography.

Generally, the cost of intellectual property associated with cell phone radio standards has been far higher than devices based on open standards such as Wi-Fi or WiMAX. That means that devices with cellular radios have been more expensive, as have the network equipment costs. I doubt industry players — including Qualcomm, which own LTE patents — are going to be eager to reduce their potential royalty income in exchange for letting Via manage the licensing process. Especially since folks at many of these firms already have the staff and knowledge to handle cross-licensing agreements.

Testing UMTS protocols

Testing UMTS by Dan Fox, Anritsu

Its nearly three years since I wrote an FAQ on UMTS Testing. So when I got my hands on this book the other day, I so wanted to read it. It would be a while before I manage to go through the book in detail but my initial impression is that this book looks quite good.

Since the book deals with Protocol Testing, the testing has been grouped into three categories:

1. Integration Testing
2. Conformance Testing
3. Interoperability Testing

There is a chapter explaining each of these. The Conformance testing is of interest to me as I have been involved directly and indirectly with this for quite some years now. The book explains the process, standards required and submission of tests to GCF/PTCRB.

For those whom testing does not hold much charm, they can gain greater understanding of the concepts by reading Part II of the book. One thing I really liked in this book is that the diagrams explain the concepts very well. Rather than copying them straight from the 3GPP specifications, they have been improved and re-done by the author. Basic things like 'Dynamic TFCI selection' and 'Layer 2 transport channel processing flow for the 12.2 kbps RMC' are explained clearly using the diagrams.

There is just the right amount of detail in the chapters for Physical Layer, Layer 2 (MAC, RLC, PDCP) and Layer 3 (RRC, NAS). Further chapters show message flow sequence charts explaining things like 'setting up of speech call' and 'location updating procedure'. I have some basic sequence diagrams for message flow in the Tutorial section but the ones in the book are comparatively more detailed.

The book mainly covers UMTS, with an introduction to HSPA. It would be worthwhile to have the next edition covering LTE in detail. The main reason being that there are lots of changes in the case of LTE. The Air Interface has changed, the channels are different. The NAS messages and entities are different. UMTS (and HSPA) use TTCN-2 for testing but LTE uses TTCN-3. UMTS does not use MIMO (MIMO available for HSPA from Release 7 onwards) but LTE would generally always use MIMO.

Overall, this seems to be a useful book and I am looking forward to reading it in detail.

Golden-i: Futuristic Bluetooth Headset with Virtual PC Display

Microdisplay technology maker Kopin Corp. reports it has partnered with Motorola Inc. to introduce a wireless headset with a high-definition virtual display and speech recognition for remote control of things such as smart phones and PCs. Taunton-based Kopin (Nasdaq: KOPN) teamed up with Motorola’s Enterprise Mobility Solutions division to put a 15-inch virtual PC display together with a microphone and earpiece into the headset it calls the “Golden-i.” According to material from Kopin, the Golden-i uses Bluetooth 2.0 to connect to the devices, as well as to Bluetooth-enabled peripherals such as a mouse, touchscreen or keyboard. Golden-i runs on the Microsoft Windows Embedded CE 6.0 R2 operating system, and once connected, users will see their PC desktop screen on the 15-inch virtual display. To control the connected device hands-free, Kopin is incorporating the VoCon3200 software from Burlington-based Nuance Communications Inc. Golden-i also uses Nuance’s text-to-speech application to read back documents, e-mail messages, web content or any text on the display screen. According to Kopin officials, it supports up to 20 languages. If no interface peripheral such as a Bluetooth mouse is available, Golden-i can use its built-in Hillcrest Labs 6-axis, real-time position tracker to allow control of the connected device using head gestures. The device also provides a mini-USB port, and a removable Micro SD card slot taht can support up to 32GB of memory. The target market for Golden-i, according to Kopin, is remote workers looking to quickly connect to a PC or network for information, such as outside sales staff. It is also aimed at network support personnel, as it can support connections to multiple devices, Kopin said.Kopin, which counts the defense industry as a major customer, last December reported it had landed $3.1 million from the U.S. military for displays used in weapon sights. Once connected to a host device, such as a PC, users see their PC desktop screen on the 15-inch virtual display and with Nuance’s VoCon3200 software they can control it using voice commands in a number of languages. Kopin claims this software provides more than 90 percent proficiency straight out of the box, and the more it is used, the better it works. Golden-i requires no push-to-talk buttons and is ready to respond to a user’s request whether in light hibernation or during intermittent use. Golden-i also readily accepts conventional user interface from any host device touch screen, keyboard or wireless mouse and integrates Nuance text-to-speech, enabling Golden-i to read back any text displayed in a number of common languages. Running on the Windows Embedded CE 6.0 R2 platform, Golden-i can remotely wake a PC from practically any location and, when work is finished, the PC can be placed in hibernation with a single spoken command. The headset can also remotely control up to seven other devices or networks at one time, similar to the way users control software applications on a PC desktop. It operates much like a highly mobile server, a hub between various host devices. If a USB interface or removable memory is required, Golden-i provides a mini-USB port and a removable Micro SD card slot capable of supporting up to 32GB. Supported by Texas Instruments’ third generation OMAP dual processor platform, a single 1200 mA/hr li-ion battery should provide more than eight hours of standard use. While the Golden-i can be used just about anywhere, it is designed for “mobile information snacking”, rather than continuous use over long periods. Initial development of the unit has focused on industrial applications, so Kopin is seeking to engage several industrial organizations in several months of in-depth field testing and evaluation. Kopin hopes to incorporate any improvements and refinements uncovered during testing into its Golden-i products, which are expected to be available in 2010. Kopin believes Golden-i will free users from the need to carry a PC or laptop about with them. Freedom from work, though, is another matter entirely. You can read all about the hardware and software details and features of this device here.

Inter symbol and inter carrier interference (ISI and ICI) in OFDMA

Radio channel are random, fast changing and error prone. In a wireless system the variation/fluctuation in the received signal is called fading. The goal of the wireless system design is to overcome different types fading and provide reliable and efficient transmission. Generally there are two types of fading.

• Large scale fading: It is the fluctuation in the average signal strength over a large distance and is caused by terrestrial change. This occurs when a mobile travel from a lake to mountainous are to a lake area or from an open area to a tall buildings area. Large scale fading can be mitigated by controlling the transmit power.
• Small scale fading: Occurs as a result of the fluctuations in the received signal strength over a small distance and is caused by multipath and Doppler's shift. Doppler shift refers to the change on frequency of the signal because of relative motion between the transmitter and the receiver.

The figure here shows the multipath propagation for a signal. Signal goes from transmitter to the receiver through multipath that have different lengths i.e. path 1, path2 and path 3. The signal from different path arrives at the receiver at different times although it’s originated from the same source. The received symbol as shown below is longer than the duration of the original symbol.

Delay spread can cause adjacent symbols to interfere at the receiver. As a result of the multipath the delayed version of the first symbol shifts into the next symbol time and thus causes overlap between he symbols. In OFDMA this is taken care of where more time is give for each symbol to be received at the receiver by inserting a guard time.

The Doppler shift introduces another type of interference in OFDMA i.e. inter carrier interference (ICI). OFDMA divided the spectrum into narrowband subcarriers and they are tightly spaced simply because they are orthogonal. One of the requirements for orthogonality is to maintain the subcarrier spacing exactly the reciprocal of the symbol period. The figure below shows the frequency shifts thus changing the subcarrier spacing which results in the loss of orthogonality. This loss of orthogonality creates interference among the signals which is called as ICI. Since the subcarriers in OFDMA are usually very narrow hence the OFDMA system becomes very sensitive to ICI. ICI destroys the orthogonality of the OFDMA system which is overcome by the use of cyclic prefix mechanism.

Under this mechanism OFDM symbols are extended into periodical symbols i.e. redundant information is sent out to ensure that analysis can be conducted on the undistorted information and is called as cyclic extension.

It can be implemented by copying the portion of the original symbol from the end and attaching it to the front or copying it from the front and attaching it to the end. Since OFDMA has already assigned the guard time to defeat ISI, cyclic extension can be put into the guard time interval. This is called cyclic prefix. With cyclic prefix used the delayed version of the previous symbols cannot shift into the useful time of the current symbol so ISI is eliminated as well. Also the cyclic prefix provides redundant information and allows spectral analysis in the receiver to maintain the orthogonality of the subcarriers. Thus the cyclic prefix can be used to deal with both ISI and ICI.

The above concepts can be summarized in teh form of the picture below