Simplicity of LTE and its differences with UMTS RRC

LTE is gaining pace as the days pass by and everyday we hear some sort of milestone achieved by some company towards the ultimate aim of LTE product. RRC is one of the main components of Layer in the LTE protocol stack just as it was in UMTS. Certainly LTE RRC looks simpler in terms of the no of states and off course the length of the RRC document. Below are some of the important changes in LTE RRC and its difference with the UMTS system.

RRC State: In LTE there is only 2 RRC states i.e. RRC_IDLE and RRC_CONNECTED whereas in UMTS system RRC has a 5 state i.e. IDLE, CELL_FACH, CELL_DCH, CELL_PCH and URA_PCH. One of the reasons why we don’t have CELL_FACH and CELL_DCH state is because there is no concept of common and dedicated transport channel in LTE. In LTE the data transfer will be done through the defined shared transport channel. Therefore this will simplifies the RRC State machine handling and improves RRC performance. This will also simplify the RRM algorithm which decides RRC states.

Signalling Radio Bearers: In LTE there is only three SRB is defined i.e. SRB0, SRB1 and SRB2 whereas in UMTS system RRC has 4 SRBs i.e. SRB0, SRB1, SRB2 and SRB3 (optional).
SRB 0: In LTE SRB 0 use RLC TM entity over CCCH logical channel in DL whereas in UMTS system it SRB 0 is sent on RLC UM entity over CCCH logical channel in DL.

MAC entity: In LTE there is only one MAC entity which needs to configured whereas in UMTS system there is 4 different MAC entity based on different type of transport channel i.e MAC-d (DCH), MAC-c/sh (FACH, DSCH), MAC-hs (HS-DSCH) and MAC-e (E-DCH). In UMTS system the state machine which is handling MAC configuration is quite complex. During state transition from CELL_FACH to CELL_DCH or CELL_DCH to CELL_FACH lots of signalling was involved. In LTE, since there is only one MAC entity which is easier and simple to configure and thus have very simple State Machine.

Radio Bearer mapping: In LTE Radio bearer mapping would be much simpler than the UMTS system because of there is no common and transport channel defined in LTE.
In LTE there is no RRC connection mobility defined like cell update and URA update.

Domain Identity: In LTE, there is only one domain identity i.e. PS domain and which is implicit no need to specify anywhere in signalling unlike UMTS system which has CS domain and PS domain. Because of a single domain in LTE the signalling overhead and complexity in RRC design has been reduced.

System Broadcast Information: In LTE, MIB includes a limited number of most frequently transmitted parameters and SIB Type 1 containing the scheduling information that mainly indicates when the SI messages are transmitted where as in UMTS system, MIB includes the frequently transmitted parameters was well as scheduling information.

Channels: In LTE RRC there is no need to define the downlink transport channel configuration in the RRC Reconfiguration message as it uses only shared channel. This will reduce signalling message size effectively. All DL-SCH transport channel information is broadcasted in system information.

Power Consumption: The above point introduces another very critical feature of DRX calculation since all DL data is on the shared channel. E-NB can tell the UE when to decode/listen over the radio frame. This will optimize UE power consumption.

Paging Type: Since there is no CELL_FACH and CELL_DCH state in LTE there is only one type of paging required where as in UMTS system there is two type of paging defined.
Reconfiguration: In LTE there is only one reconfiguration message to reconfigure all logical, transport and physical channel where as in UMTS system there are number of reconfiguration message i.e. RB reconfiguration , TRCH configuration, PHY configuration. Thus there is less signalling message or overhead in LTE for the reconfiguration.

Reduced Latency: Since there is no RNC or NBAP protocol in LTE, this reduces the latency of the RRC connection establishment and RB management procedure.
Single UE identity: Since there is only one shared MAC entity, there is no need to define URNTI, ERNTI, HRNTI, SRNTI etc in LTE.

No Activation time: In LTE, there in no need to define activation time. Because of this there are lots of synchronizing complexity in 3G-RNC systems i.e. Synchronizing Radio link procedure based on activation time, synchronizing between the various MAC entity. This reduces significantly latency during establishment and reconfiguration of radio bearers.
RRC State: In LTE, there in no need to specify the RRC State in RRC message.

CQI Reporting: For network control mobility, there is one feature which become very important and critical i.e. CQI Reporting. As in LTE the CQI reporting should be fast and correct for taking decision for mobility.

Signalling connection release: There is no signalling connection release procedure in LTE, since there is only one domain i.e. PS domain. Also the UE context is shared between the MME and ENB and if UE is active in ENB then it should be active in MME also.

3GPP Demystified

3GPP held a workshop in June called 'The 3GPP Seminar': All you always wanted to know about 3GPP but were too afraid to ask.

The following topics were covered:

• Introduction to the Third Generation Partnership Project
• Meetings of the technical groups
• Writing contributions which count
• Rules and regulations
• Following the work
• Preparation of meetings
• a guide for chairmen
• The Work Plan
• Work Items
• Numbering scheme for TSs and TRs
• Drafting and maintaining the Technical Specifications
• The Drafting Rules
• 3GPP TR 21.801
• Change Requests
• Hints for Getting Results
• a guide for chairmen
• Elections and voting
• Funding
• Legal
  
  

You can download/view the presentations on the 3GPP site:

http://www.3gpp.org/ftp/workshop/2009-06-16_3GPP_Methods_Seminar/

or

http://ftp.3gpp.org/workshop/2009-06-16_3GPP_Methods_Seminar/

12 megapixel Sony Ericsson Satio coming next month

What can you do with a 12 megapixel camera in the phone? I for sure would be doing 'Megapixel Microscopy' and probably click 4-5 photos in a year.

Sony Ericsson recently announced Satio which provides you access to all your media in one place – just tap directly into your favourite features with the five standby panels and you’re ready to go. First introduced in Barcelona as the ‘Idou’, Satio puts the future of mobile entertainment in the palm of your hand. You can watch your favourite movies on the bus or catch up with your TV shows while on your lunch break thanks to Satio.

“With Satio you can enjoy any form of entertainment anytime, anywhere. Whether its music or movies you will never be more than a tap away from your favourite tracks or shows,” said Fredrik Mansson, Market Business Manager at Sony Ericsson. “Just tap directly into your favourite videos and music with the unique full touch media menu, standby panels and music player. Snapping perfect pictures also just got so simple thanks to the 12.1 megapixel camera, intuitive touch focus and Xenon flash. Share them with your nearest and dearest via your social networking site, produce huge prints and you can even comment directly on your images.”

Download exciting music, movies and games from PlayNow™ arena to personalise your entertainment experience on Satio and enjoy them in crystal clear 16:9 widescreen format. PlayNow™ arena provides a full range of mobile entertainment available by dual download to both your PC and mobile phone with specially developed ring tones and music tones and DRM-free music tracks and TrackID™ charts from around the world.

The Phone has 7.2Mbps HSDPA and 3.6Mbps HSUPA capability. There is a different model for US, China and the rest of the world. Thankfully it comes with 8GB SD card so you wont have to worry about transferring your images after every 10-15 photos.

The phone is going to be available in Sep 09 in UK and probably elsewhere.

'Sexting' craze catching on in UK as US teen hangs herself

Eighteen-year-old Jessica Logan had it all. She was bright, pretty and popular. Her mum Cynthia describes her: "She was vivacious, she was artistic, she was fun, she was a good kid."
She was completely in love with her boyfriend but one day she sent him a text, a nude photo of herself, to show him how much she cared.

When they broke up he sent the picture to hundreds of teenagers in their town in Ohio to get back at her.
Jessica's friend Lauren Taylor told reporters: "She was being attacked and tortured. "When she would come to school, she would always hear, 'Oh, that's the girl who sent the picture'.''

The bullying spiralled out of control and Jessica began skiving off school. In June last year she couldn't take it any more and killed herself.

I wrote about 'Sexting' some months back and sure its become much more popular and dangerous since then.

According to the charity Beatbullying, one in three 11-18 year olds has received a "sext" – a sexually explicit message sent by phone or email – and girls are regularly being bullied into taking and sharing explicit photos of themselves. There is also a fear that these images may be falling into the hands of sex offenders. It is time for this private practice taking place on the tiny screens of children's mobile phones to be brought to light in the public domain.

The schools minister (UK), Diana Johnson, said children who were facing sexual bullying should tell a teacher. "We are committed to tackling all forms of bullying – including bullying using the internet and mobile phones, and sexual bullying," she said. "It is important that young people being bullied know that they can report it and that it can be stopped.

Maybe in couple of years we may have 'Minister for Mobile Communications' in UK or US to handle such problems :-)

Didnt I tell you, phones are too complicated ;)

As the former head of the British army, General Sir Mike Jackson oversaw a range of regiments armed with some of the most complex weapons and technology ever invented.

But yesterday, the general was left embarrassed live on television after he was defeated by a ringing mobile phone.His phone went off twice during an interview with the BBC's economics editor Stephanie Flanders, who was standing in for Andrew Marr.

Jackson was talking about compensation given to wounded soldiers when the mobile began to ring.

Flanders told the general: "You'll have to turn that phone off." Jackson apologised and after sheepishly fumbling with some buttons, managed to silence the call and put the phone in his pocket – only for it to ring again.

As he tried to turn it off once more, technology appeared to get the better of him.

In the end, Jackson lost his patience, turned around in his seat and flung the handset off camera across the studio in exasperation. After the sound of a heavy crash rang out, he returned to face Flanders and the interview with as straight a face as he could manage.

Now even Texting can be dangerous :-)

Police say a truck driver was texting on one mobile phone while talking on another when he slammed into a car and crashed into a swimming pool.

Niagara County sheriff's deputies say 25-year-old Nicholas Sparks admitted he was texting and talking when his flatbed rescue truck hit the car in Lockport, which is outside Buffalo.

The truck then crashed through a fence and sideswiped a house before rolling into an in-ground pool.

Police say the 68-year-old woman driving the car suffered head injuries and was in good condition. Her 8-year-old niece suffered minor injuries.

Sparks was charged with reckless driving, talking on a cell phone and following too closely.

iPhone Apps and the Smartphones's Apps war

Smartphones had done amazing this to the consumers in the past couple of years especially after the launch of iPhone. These days there is immense concentration on the development of quality applications Application which can lure the customers in real time and are useful to them. I remember initially mobile games created similar kind of furore but I personally believe that this is different. These days application are developed not only for fun sake but also providing the customers some really value added service.

iPhone certainly is leading in the race in this regard and application developers are hugely receptive to the ideas which can be translated into a iPhone application.

Lance Stewart is one such person who came up with the idea of latest iPhone application called Tube Exits.

It came to him when he was trying to get out of Oxford Circus tube station in a hurry. Anybody who’s has experience the London’s train station during th rush hours knows very well that you find yourself behind a huge crowd of people blocking the way to the exit.

After experincing similar this Stuart thought that what he needed was to get the jump on the crowds by knowing which carriage he should board to arrive at the platform exit. If he somehow knew, for every station platform on the London Underground network, which carriage would arrive at a station next to the platform exit, he would never be stuck behind foot-dragging tourists or daily commuters again.

He thought it would be good idea to put all this information into the form of an iPhone application for other commuters. Dreaming of making something out of it he compiled the information for more than 700 platforms at London Underground's 268 stations. As he was not the person who can develop the app of his own so together with the collected information he approached an apps developer with his idea.
The outcome of this Stuart’s initiative and idea was the Tube Exits app for iPhone which was launched on 16ht June and has become very popular since then.

The app comes in two versions: One is free but only gives you the information for the Underground's busiest 12 stations; the other costs £1.79 and covers the whole network. This price is probably a price of a zone 1 ticket, but you could use it again and again.

Stewart is now involved in developing a similar app for the Paris Metro and sees no reason why his original idea can't be applied to other metro networks around the world.

Tube Exits is just one of an estimated 100,000 apps that will exist by the end of this year. Most of the apps these days are mobile applications designed to be used on Smartphones such as iPhones or BlackBerrys.

Recently the apps industry has grown exponentially where the total number of Apple's App Store downloads only recently passed the 1.5bn mark.

The App Store's success is huge incentive for Apple and is really giving a tough time to its competitors such as Research in Motion (who make BlackBerrys) and Nokia (the world's biggest mobile phone maker). The App Store's staggering success has led nearly every maker of a smartphone operating system to mimic Apple's business model: make it very easy for smartphone users to buy or freely download software created by from third-party developers.
Indeed Apple has become an icon phone and at the moment Apple has something of a stranglehold on apps e.g. Tube Exits can only be used on Apple mobile hardware (ie iPhones and iPod Touches).

What's especially striking about apps is how quickly they have become popular and are the real money spinners for smartphone companies specially Apple. I remember it very well when the iPhone was launched, there were many sceptical voices. It was too expensive, too readily nickable, too much of a triumph of what techies could do over what customers wanted to be for it to be a success. Apps have changed all that where Apple gets a significant chunk of revenue from the sale of its Apps. Apple is smartly doing what Microsoft has been doing until now, binding the applications and software to its products.

Apple is also not leving any stone unturned in fighting for the superiority of it’s application. This can be best provide by Apple recent victory in front of the advertising watchdog, with a ruling that it is free to claim its iPhone applications store is superior to a rival service offered by Google.
The Advertising Standards Authority rejected complaints from fans of Google's G1 smartphone that a TV ad for Apple's App Store was misleading.

"Yep, there's an app for just about anything," a voiceover in the advert said. "Only on the iPhone."

The days ahead will be interesting and messier in terms Smartphone companies claiming for smart and beautiful apps.

LTE Band 13 mystery

Interesting observation from Hooman Razani in LTE university blog:

It was in a classroom, after I had opened Technical Specification 36.101 for handset radio transmission and reception that I suddenly noticed for the first time something odd about Band 13.

I said to the class without hesitation, Band 13 [UL = 777 MHz-787 MHz & DL = 746 MHz-756 MHz] has the uplink and downlink reversed! In contrast to all other FDD bands in the table (and many other bandplans elsewhere), in this band, the higher frequency is allocated to the mobile device and the lower frequency to the base station. The normal practice of FDD paired band allocation has to do with attenuation properties of the carrier frequency and the availability of the power. The mobile side has usually been allocated the “easier” lower-frequency portion of the band which experiences smaller amount of attenuation and therefore requires less power for closing the uplink. A reversal of this allocation strategy in band 13 is a sure sign that some other problem is lurking in the background, namely interference in the form of spurious emissions.

The 700MHz band is divided into four paired blocks, A, B, C and D (an unpaired E Block is also available). The A and B blocks are guard bands. The C blocks (LTE Band 13) in this upper 700MHz band were the main object of last year’s auction. 12MHz in the middle of this spectrum belongs to the Public Safety.

A – C – D – B – [Public Safety] – A – C – D - B

A look at the structure of the auctioned UHF band shows that upper portion of Band 13 is closer to the public safety band. In order to reduce the effects of interference to the public safety band and other bands due to intermodulation effects of this carrier, the higher more “difficult” frequency has been allocated to the lower powered handset. On the other hand we can expect a slight enhancement in indoor coverage for band 13, due to further lowering of the downlink frequency .The question to ask is if this maneuver is enough to suppress the spurious emissions caused by the handsets to nearby bands. Further details after initial deployment will shed light on the mysterious case of band 13.

Nortel Acquisition and Ericsson Gameplan

Bankruptcy courts in Canada and the United States unanimously approved Nortel Networks Corp.'s request to sell its main wireless business to Swedish rival LM Ericsson.

The US$1.13-billion sale will deliver to the Swedish telecom firm Toronto-based Nortel's CDMA, or code division multiple-access technology, an older system, but one still widely deployed by mobile-phone carriers. CDMA is expected to continue to be in use in developing markets like Asia for the next several years.

However, the most lucrative portion of the sale, analysts say, comes in Nortel's long-term-evolution technology, or LTE. Nortel said it has spent as much as US$200-million annually developing the next-generation wireless gear that is expected to become the global standard in the future.

"Nortel still owns all of the LTE patents," Nortel counsel Derrick Tay said in court. Mr. Tay said Nortel owned some 5,500 patents. Of those, 600 were being "transferred" to Ericsson while none of the LTE intellectual property was being sold. Instead, Nortel will be licensing them to Ericsson, he said.

I am curious as to what does it mean by licensing the LTE patents considering the fact that Nortel is bankrupt. If the license period is something like say 99 years then it shouldnt really matter for Ericsson. I am not sure just making a guess.

Lynnette Luna, Fierce Wireless has a very interesting take on this:

Ericsson and Nokia, once the staunchest opponents of CDMA technology, found themselves in a bidding war for bankrupt Nortel's CDMA assets. The war ended on Friday with Ericsson on top and willing to pay $1.13 billion for most of Nortel's CDMA and LTE assets.

Ericsson had tried to make a go of it in the North American CDMA market following its purchase of Qualcomm's infrastructure business that was part of its IPR settlement with Qualcomm in 1999. It subsequently ended the business after failing to penetrate this market since Qualcomm didn't have much of an installed base. Nokia, now Nokia Siemens Networks, never tried to play in the North American CDMA market, and thus has a weak North American market share overall at around 5.5 percent.

However, Ericsson this year has made significant headway into the U.S. market, scoring a big LTE deal with Verizon--at the expense of Nortel--and winning a $5 billion CDMA outsourcing agreement with Sprint Nextel. Did it really need to spend $1.13 billion to gain more market share?

The answer is yes. Despite winning these two U.S. deals, the biggest criticism of Ericsson has been its lack of CDMA expertise--whether managing a network or migrating CDMA operators to LTE. Now it has both. Given the fact that Nortel's CDMA gear is in a significant portion of CDMA networks operating around the world, Ericsson now has a great story to tell. It needs that CDMA expertise to migrate customers from CDMA to LTE--especially since voice traffic will continue to run over CDMA networks while data gets routed over LTE for the foreseeable future.

For Ericsson, it's no longer about getting a foot in the door. It's about crushing the competition. Ericsson is looking forward to a future when both WCDMA and CDMA operators look to it to help them migrate to LTE. But as Ericsson CEO Carl-Henric Svanberg said on the conference call this morning, "CDMA will be the first markets to migrate to LTE so therefore it is important to us."

Meanwhile, a deal like this could be the nail in the coffin for some vendors. It's certainly not good news for NSN, which would have boosted its North American market share to 30 percent had it won the assets. And Chinese vendors ZTE and Huawei have been trying hard to make inroads into the North American market through CDMA. This deal certainly hampers those efforts.

And Alcatel-Lucent just saw its major competitor become significantly stronger. Alcatel-Lucent was the vendor with the better CDMA-to-LTE conversion story while Nortel was stuck in bankruptcy limbo.

Of course, it's not just about getting a stronger foothold in LTE. Nortel's CDMA business is a money-maker, and Ericsson executives on the call this morning said they believe the unit will continue to be profitable for the next few years as operators keep investing in their CDMA networks. There are actually operators looking to deploy CDMA EV-DO Rev. B. And don't forget the services market, a major growth engine for Ericsson. Ericsson said the deal will be earnings per share accretive within the first year.

Q2 Mobile sales: No surprises but lots of good news

Nokia, the world's largest maker of mobile phones, reported Thursday that its second-quarter operating profit fell 71 percent to 427 million euros ($600 million) from 1.47 billion euros during the same quarter a year earlier.

The company also reported that sales fell about 25 percent to 9.9 billion euros in the second quarter. But sales were up 7 percent sequentially from the first quarter of 2008.

Nokia shipped 103.2 million units during the quarter, which was down about 15 percent compared with a year earlier. But shipments were up 11 percent sequentially compared with the first quarter of this year.

Nokia said that it increased its market share sequentially for global sales of mobile phones to an estimated 38 percent. And its smartphone market share grew sequentially to 41 percent.

Toward the end of the second quarter, Nokia brought its N97 smartphone to the U.S. market.

It was bound to happen, but we didn’t think the Nokia N97 would outsell the Nokia 5800 quite as quickly as it has. However, from sales figures that have just been released, it looks like the big fight of the summer is going to be between Nokia’s two touchscreen smartphones.

The top ten phones currently being sold by Vodafone looks something like this:

1. Nokia N97 32GB

2. Nokia 5800

3. Sony Ericsson W595

4. Sony Ericsson C510

5. Samsung Jet

6. Samsung Tocco Ultra Edition

7. Samsung Steel L810

8. Nokia 6300

9. BlackBerry Storm

10. HTC Magic

South Korean company Samsung Electronics Co., Ltd recently announced the earnings results for the second quarter of the ongoing year. Globally, the company registered an 11.7 percent increase in revenues during the quarter on a yearly basis, reaching 32.51 trillion Korean won, and posted 2.52 trillion won operating profit, up 436 percent compared to the previous quarter of the year.

Samsung’s Telecommunications business also went up compared to the same time frame last year, reaching 10.04 trillion won in revenue, or a 27.4 percent increase, while the operating profit was of 1.00 trillion won, with a 10 percent margin. During the three-month period, the company says, its mobile phones sales reached 52.3 million units, marking a 14 percent increase compared to the previous quarter.

LG Electronics posted a record quarterly profit on strong mobile phone and TV sales, helping it win market share from rivals Nokia and Motorola today. However concerns over weaker margins may stall a rally in its shares.

LG, which trails Nokia and Samsung in mobile phones, sold a record 29.8 million handsets in the second quarter, up from 22.6 million units in January to March.

It posted an 11 per cent operating profit margin in handsets, compared with 6.7 per cent in the first quarter, a figure Choi said was "pretty remarkable."

The company's operating profit margin was 7.8 per cent in the second quarter and was at 4.3 per cent for all of 2008.

Fourth ranked Motorola is working to narrow losses through cost cuts in the face of sharp drops in sales, while world fifth maker Sony Ericsson is also braced for a tough second half of 2009 as a demand slump hits its stronghold mid-range products focused on camera and music features.

Apple's quarterly results were better than forecast, thanks to strong iPhone sales, including its new 3GS model.

Net profits hit $1.23bn (£953m), or $1.35 a share, in the fiscal third quarter to 27 June, from $1.07bn, or $1.19 a share, a year earlier.

The US technology giant sold more than 5.2 million iPhones in the quarter, seven times more than a year earlier.

Apple chief financial officer Peter Oppenheimer said: "We are very proud of this result, particularly given the economic climate around us."

He also admitted that Apple was "currently unable to make enough iPhone 3GS to meet high demand and we are working to improve that".

Apple also hopes to make the iPhone available in more countries than the current 18, including China "within a year".