Tuesday, 1 June 2010

LTE Femtocell Enhancements for Release-9

LTE Release 9 provides further functionality to support more efficiently HeNBs operation and to provide a better user experience. The key functionality added the Radio Access Network for HeNBs in Release 9 are:

• A novel Hybrid Cell concept
• Management of out-of-date CSG info
• Inbound Mobility (including proximity reports)
• Access Control
• Operation, Administration and Maintenance for HeNB
• Operator controlled CSG list
• RF Requirements for TDD and FDD HeNBs

Nomor Research have recently released a paper that covers all these issues and much more. Titled "LTE Home Node Bs and its enhancements in Release 9", its available to download here.

Monday, 31 May 2010

Using Femtocells abroad Illegaly

Back in 2008, I blogged about Femtocells and stealing of Spectrum. Since the rollout of Vodafone Suresignal, I am seeing people discuss it more and more about using the Femtocells abroad. I should say as I have in the past that this would be illegal and I wouldn't encourage anyone to do it but as couple of people have mentioned to me in private that they have managed to do it I would like to hear if someone else has managed this feat.

Since you need to have the IP address belonging to the country your femtocell is registered to, this means that you need to use a VPN along with the Femto to make sure that your IP packets look like they are coming from the country. At the same time your mobile should only be working with your Femto in a sheilded space (basement kind of location preferably to avoid any GPS chip picking up your location).

Another way you can give your game away to the operator is to handout from the mobile to a foreign network. It will definitely send some bells ringing.

Sunday, 30 May 2010

ng-connect LTE car from ALU

Back in the LTE World Summit 2010 there was this ng-connect LTE car demo. I wasn't able to get a demo as there didnt seem to be anyone willing to be filmed for the blog. The first I heard about this ng.connect program was last year when I blogged about the case for early LTE in USA.

The ng connect program ecosystem brings together lots of companies that are collaborating from research to sales and marketing. If you click in the picture above you will be able to see the enlarged image and at the bottom you can see the names of these companies. The car is ofcourse Toyota but I wasnt able to see that in the list of companies.

The following Youtube clip gives an introduction to the connected car



The following is from the Demo from France. In January 2010, Alcatel-Lucent launched for the first time in Europe the ng Connect LTE Connected Car in its Velizy, France facility, showcasing the capabilities that Long Term Evolution (LTE), the next generation of mobile networks, will bring to automakers, service providers, application developers and end users. Also demo'd in Velizy was the live LTE drive tour in a van, testing mobile services on a campus-wide network, demonstrating a smooth transition between 3G/HSPA and LTE networks.



The final video is slightly longer clip which shows the thought process behind the connected car.



If you havent had enough already then I would also recommend this post.

Friday, 28 May 2010

UMTS/HSPA State Transition Problems to be solved with LTE

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

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


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

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

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

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

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

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

Thursday, 27 May 2010

LTE will be known as 4G!


I have been mentioning since 3 years that LTE is 3.9G and its not 4G. In fact I have brought it up in many posts and discussions so that we do not dilute the term 4G. From my recent visit to the LTE World Summit and from the news, etc. it seems that the marketing guys won and LTE would be known as 4G.
In the picture above you can clearly see that the press releases by well known companies as well as Samsung's dongle has 4G for LTE stamped. It may be very difficult to reverse this '4G' means LTE term.
So I have now started thinking about what LTE-Advanced will be known as. Here is my attempt:
  • 5G - Not sure if people will buy this. Assuming that LTE-Advanced specs are ready by March 2011 (as is predicted) then people wont be ready to jump from 4G to 5G this soon.
  • 4G+ - Not sure if this sounds sexy enough
  • Super 4G - Boring
  • Turbo 4G - reminds me of F1
Suggestions welcome.

Police call for remote button to stop cars

From The Guardian:

British Police are urging Ministers to give them the power to stop vehicles by remote control.

In what will be seen as yet another example of the in-creasing power of Big Brother, drivers face the prospect of their cars being halted by somebody pushing a button.

The police lobby is being led by Superintendent Jim Hammond of Sussex police, who chairs an Association of Chief Police Officers technology working group which is examining the idea.

'Providing an effective means to remotely stop a vehicle is fast becoming a priority,' Hammond told a European conference. 'The development of a safe and controlled system to enable remote stopping has the potential to directly save lives.'

However, Bert Morris, deputy director of the AA Motoring Trust said: 'People don't like the idea of Big Brother taking over their driving. In years to come that might be acceptable, but it's very, very important that there's a step-by-step approach.'

Cars could be stopped by the gradual reduction of engine power so it slowly comes to a stop, or by making sure when drivers come to a halt they can not move again.

Stopping cars remotely sounds futuristic, but the basic technology is already available and used in lorries to limit the top speed to 56mph and in new systems to immobilise stolen cars.

The key is the electronics box in most new cars which, when the driver presses the accelerator or brake, sends a message to the engine to speed up or slow down. It can be programmed to limit the speed generally or according to the position of the car, established via a GPS satellite. For remote operation, a modem, which works like a mobile phone, can be used tell the car to slow down or stop.

Similar radio telemetry was used by Formula One pit crews to adjust the engines of racing cars at up to 200mph - until it was banned this year.

'The technology exists and will become more refined as time goes on,' said Nick Rendell, managing director of the Siemens business developing this technology in the UK.

A senior police officer - assumed to be the chief constable or deputy - can already give the order to stop a car remotely, but that power has rarely if ever been used, said Morris. To use any new powers more widely, police must first overcome some practical problems to reassure Ministers that vehicles would be stopped safety. Ministers will also want reassurances that drivers would not be mistakenly stopped.

ACPO insists that it would only introduce the technology when it was safe. It is calling on the Government to introduce the legislation which it says will be vital to stop vehicles when - as expected - manufacturers develop tyres that run when they are flat. This will make 'stingers' - the spiked strips thrown in front of speeding cars - useless to stop stolen and get-away cars or dangerous drivers.

It is also linked to pressure to make cars 'pointless to steal' because of growing concern about more violent car crime as vehicles become harder to take. The RAC Foundation recently found there were as many as 1,200 car jackings in Britain last year.

Another link is to technology which would stop cars going above certain speed limits - either a fixed maximum such as 70mph, or varying according to the local limit.

The system could even be programmed to reduce speeds below the limit in bad weather or when school children were expected to be about, said Robert Gifford, director of the Parliamentary Advisory Committee on Transport Safety, which believes the technology could cut the 3,420 deaths a year on Britain's roads by 59 per cent.

Experts now believe the technology could start to be used voluntarily by the end of the decade and ultimately could be made mandatory.

Wednesday, 26 May 2010

Small cells and Wireless Capacity Growth

Self explanatory slide showing the impact of Small cells on the capacity growth. This is probably the best way to further increase the capacity.

Courtesy: Moray Rumney, Agilent technologies in LTE World Summit

Tuesday, 25 May 2010

Quality of Service (QoS) and Deep Packet Inspection (DPI)

One of the things I mentioned in my presentation in the LTE World Summit was that differentiation of Services based on Quality of Services is required to be able to charge the users more.
This QoS can be varied based on deep inspection of the packets which can tell the operator as to what service a particular packet belongs to. The operators can thus give higher priority to the services and applications that are recommended by them and also block certain services that can be deemed as illegal or unproductive (like file sharing or P2P).

Continuous Computing claims to be one of the market leaders in producing the DPI systems. You can read this article by Mike Coward who is the CTO and Co-founder of Continuous computing here.

There is also this very interesting paper on QoS control in 3GPP EPS which is available freely here.

Please feel free to comment or suggest how do you see DPI being used in the future.

Monday, 24 May 2010

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


The 'Cost per Bit' issue...

Cost per bit has always been an issue from operator point of view. The other day an operator tried to show a comparison of data transfer with SMS. Though this may make some of us feel guilty that we are ripping these poor operators off ;) in reality most of us agree that it is the other way round.

A slightly older report from Ericsson suggested that from operator point of view, 1GB data transfer can cost as low as 1 euro.

So if we now plug in the above information into the slide below, presented by Moray Rumney of Agilent in the LTE World Summit, we can see that the operators have been earning massive profits on our behalf.



With Mobile broadband becoming more common and cheaper, users may not be willing to pay any more than they are now. At the same time, they may expect the speeds to keep increasing at regular intervals. The operators will soon be forced (if not already doing so) to offer QoS based packages which can help them boost their revenue and provide better QoE to the higher paying users.

I will cover this issue of QoS, QoE and DPI in the upcoming posts.

If you are wondering along the lines of how to reduce this cost per bit then I would recommend you to go back and have a look at this discussion on Martin Sauter's blog.
If you are thinking along the lines of increasing ARPU with LTE, then please see my presentation here.