eMBMS: evolved Multimedia Broadcast Multicast Control

I spent a lot of time working on MBMS but operators decided not to roll out the technology. It was killed in its infancy. Earlier I blogged that MBMS wont be present in Release 8 but now there is interest in some quarters about MBMS being present in Release 9.

As I have mentioned earlier, the main advantage of MBMS over other TV technologies is that no additional infrastructure is required, the same technology and spectrum is used as for the 3G/LTE case and user interaction is possible thereby involving participation.

At the moment, I was only able to see eMBMS information in 3GPP TS 36.300 but I am sure more is on way soon. Section 15 of 36.300 is dedicated to eMBMS information.

In E-UTRAN, MBMS can be provided with single frequency network mode of operation (MBSFN) only on a frequency layer shared with non-MBMS services (set of cells supporting both unicast and MBMS transmissions i.e. set of "Unicast/MBMS mixed cells").

MBMS reception is possible for UEs in RRC_CONNECTED or RRC_IDLE states. Whenever receiving MBMS services, a user shall be notified of an incoming call, and originating calls shall be possible. ROHC is not supported for MBMS.

So where does it fit in the overall architecture?



Multi-cell/multicast Coordination Entity (MCE): The MCE is a logical entity – this does not preclude the possibility that it may be part of another network element – whose functions are the allocation of the radio resources used by all eNBs in the MBSFN area for multi-cell MBMS transmissions using MBSFN operation. Besides allocation of the time/ frequency radio resources this also includes deciding the further details of the radio configuration e.g. the modulation and coding scheme. The MCE is involved in MBMS Session Control Signalling. The MCE does not perform UE - MCE signalling. When the MCE is part of another network element, an eNB is served by a single MCE.

E-MBMS Gateway (MBMS GW): The MBMS GW is a logical entity – this does not preclude the possibility that it may be part of another network element – that is present between the BMSC and eNBs whose principal functions is the sending/broadcasting of MBMS packets to each eNB transmitting the service. The MBMS GW uses IP Multicast as the means of forwarding MBMS user data to the eNB. The MBMS GW performs MBMS Session Control Signalling (Session start/stop) towards the E-UTRAN via MME.

“M3” Interface: MCE – MME: An Application Part is defined for this interface between MME and MCE. This application part allows for MBMS Session Control Signalling on E-RAB level (i.e. does not convey radio configuration data). The procedures comprise e.g. MBMS Session Start and Stop. SCTP is used as signalling transport i.e. Point-to-Point signalling is applied.

“M2” Interface: MCE – eNB: An Application Part is defined for this interface, which conveys at least radio configuration data for the multi-cell transmission mode eNBs and Session Control Signalling. SCTP is used as signalling transport i.e. Point-to-Point signalling is applied.

“M1” Interface: MBMS GW – eNB: This interface is a pure user plane interface. Consequently no Control Plane Application Part is defined for this interface. IP Multicast is used for point-to-multipoint delivery of user packets.

It is not precluded that M3 interface can be terminated in eNBs. In this case MCE is considered as being part of eNB. However, M2 should keep existing between the MCE and the corresponding eNBs. This is depicted in Figure above which depicts two envisaged deployment alternatives. In the scenario depicted on the left MCE is deployed in a separate node. In the scenario on the right MCE is part of the eNBs.

It will be possible to have an MBMS Dedicated cell or a MBMS/Unicast mixed cell. For transmission, it will be possible to have a Single-cell transmission or Multi-cell transmission. Multi-cell transmission where the safe information is sent synchronously over multiple cells will have an advantage of receivers being able to combine information from Multiple cells and also to roam in the area of transmission seamlessly.

More information when detailed specs are available.

Dilbert humour on Mobile Rebates

Missed this one earlier but otherwise I am a big Dilbert fan. Thought it would be nice to end the week with.

By the way, last year I blogged about the Mobile Billing strategies which may be useful for you if you are considering getting new contract.

Texting teen falls down New York manhole

Last year there was a talk here in UK about adding padding to the lamp-posts because people were bumping into them while texting. The survey of over 1,000 Britons suggested that one in 10 had suffered an injury from a collision while sending an SMS. The research claimed that there were 68,000 SMS-related injuries in the UK last year, ranging from minor bumps to skull fractures.

Now, I read this news about Alexa Longueira, 15, whose family is suing after the teenager fell into an open manhole in Staten Island, New York, while trying to send a text message. Poor Alexa apparently suffered a fright and some scrapes on her arms and back when she fell.

Her mother, Kim Longueira, said it did not matter that her daughter was texting when she fell down the hole. "Oh my God, it was putrid," she told MNBC. "One of her sneakers is still down there."

If the case comes to court it is destined to join such infamous lawsuits as the woman who sued McDonald's after spilling hot coffee on herself, which inspired an annual award for the most ridiculous lawsuit. A glance at British legal history suggests Longueira may have actually have a chance of winning. In the 1964 case of Haley v London Electricity Board it was deemed workmen should have known a hole might pose a threat to visually impaired people.

Whether texting and walking is now so common that a court ruling will require workmen – and the rest of us – to adjust our actions accordingly remains to be seen.

Iranians start boycott Nokia campaign

The mobile phone company Nokia is being hit by a growing economic boycott in Iran as consumers sympathetic to the post-election protest movement begin targeting a string of companies deemed to be collaborating with the regime.

Wholesale vendors in the capital report that demand for Nokia handsets has fallen by as much as half in the wake of calls to boycott Nokia Siemens Networks (NSN) for selling communications monitoring systems to Iran.

There are signs that the boycott is spreading: consumers are shunning SMS messaging in protest at the perceived complicity with the regime by the state telecoms company, TCI. Iran's state-run broadcaster has been hit by a collapse in advertising as companies fear being blacklisted in a Facebook petition. There is also anecdotal evidence that people are moving money out of state banks and into private banks.

Nokia is the most prominent western company to suffer from its dealings with the Iranian authorities. Its NSN joint venture with Siemens provided Iran with a monitoring system as it expanded a mobile network last year. NSN says the technology is standard issue to dozens of countries, but protesters believe the company could have provided the network without the monitoring function.

Siemens is also accused of providing Iran with an internet filtering system called Webwasher.

"Iranians' first choice has been Nokia cellphones for several years, partly because Nokia has installed the facility in the country. But in the past weeks, customers' priority has changed," said Reza, a mobile phone seller in Tehran's Big Bazaar.

"Since the news spread that NSN had sold electronic surveillance systems to the Iranian government, people have decided to buy other company's products although they know that Nokia cellphones function better with network coverage in Iran."

Some Tehran shops have removed Nokia phones from their window displays. Hashem, another mobile phone vendor, said: "I don't like to lose my customers and now people don't feel happy seeing Nokia's products. We even had customers who wanted to refund their new Nokia cellphones or change them with just another cellphone from any other companies.

"It's not just a limited case to my shop – I'm also a wholesaler to small shops in provincial markets, and I can say that there is half the demand for Nokia's product these days in comparison with just one month ago, and it's really unprecedented. People feel ashamed of having Nokia cellphones," he added.

News of the boycott has appeared on the front page of Iranian pro-reform papers such as Etemad-e Melli, owned by the reformist candidate Mehdi Karroubi. Hadi Heidari, a prominent Iranian cartoonist, has published an image of a Nokia phone on a No Entry traffic sign.

A Nokia spokeswoman refused to comment on the company's sales in Iran.

The Iranian authorities are believed to have used Nokia's mobile phone monitoring system to target dissidents. Released prisoners have revealed that the authorities were keeping them in custody on the basis of their SMS and phone calls archive, which was at officials' disposal.

One Iranian journalist who has just been released from detention said: "I always had this impression that monitoring calls is just a rumour for threatening us from continuing our job properly, but the nightmare became real when they had my phone calls – conversations in my case.

"And the most unbelievable thing for me is that Nokia sold this system to our government. It would be a reasonable excuse for Nokia if they had sold the monitoring technology to a democratic country for controlling child abuse or other uses, but selling it to the Iranian government with a very clear background of human rights violence and suppression of dissent, it's just inexcusable for me. I'd like to tell Nokia that I'm tortured because they had sold this damn technology to our government."

NSN spokesman Ben Roome said: "As in every other country, telecoms networks in Iran require the capability to lawfully intercept voice calls. In the last two years, the number of mobile subscribers in Iran has grown from 12 million to over 53 million, so to expand the network in the second half of 2008 we were required to provide the facility to intercept voice calls on this network."

The SMS boycott, meanwhile, has apparently forced TCI into drastic price hikes. The cost of an SMS has doubled in recent days. Protesters view the move as a victory.

IP Access Virtual Fridge Notes Demo

Yesterday I blogged about the Airvana HubBub demo, so someone pointed out to me the IP access demo of Virtual Fridge notes. I saw the demo in Femtocells World Summit and wasnt clear on how exactly it worked, but this Youtube video shows it quite well.





When I was discussing this app with a friend, the first question he asked was, why cant we send an SMS directly to the person rather than using the Facebook app. I think the main reason is convinience. You need an app somewhere so why not put it in a popular social networking website. There is a plan of Femtocells being available with SIM cards. In that case it maybe possible in future to have a way where you send the SMS directly to the Femto and it can relay that SMS to any unique UE that enters its range for a limited time. I am sure someone will already be working on a similar thing ;)

Vodafone R&D people start a blog on LTE & Mobile Broadband

Its good to see R&D people from Vodafone starting their own blog. Vodafone has been very active with R&D and they also do very interesting lectures. I covered about one such lecture in Telecoms area here. Few months back I also attended an interesting lecture on Mobile Healthcare about which I blogged here. I am sure this is going to be an interesting blog with lots of useful information and insights.

You can check the blog out at: http://witherwire.betavine.net/

Airvana HubBub femtocell demo at Femtocells World Summit 2009

I blogged about the demo earlier here. Here is the video showing the live demo:

3GPP Release-10 Features and Studies

New Items in Rel-10

• Network Selection for non-3GPP Access
• Network Improvements for Machine-type Communications
• Registration in Densely-populated area (RED)
• Enhanced Home NodeB / eNodeB continuation of Rel-9
• IMS Service Continuity – Inter Device Transfer enhancements
• EEA3 and EIA3 (new Encryption & Integrity EPS security algorithms)
• Study on Mobile Haptic Services
• Study on Policy solutions and enhancements
• Study on IPv6 MigrationStudy on SR-VCC Enhancements

Items moved from Rel-9 to Rel-10

• IMS aspects of Architecture for Home NodeB
• GTP-based S8 chaining
• Multi Access PDN Connectivity
• Study on advanced requirements for IP interconnect
• Study on Unauthenticated PS Emergency Calls
• Study on Study on Personal Broadcast Service
• Study on LCS support in SAE for non-3GPP accesses
• Study on System enhancements for the use of IMS services in local breakout and optimal routing of media
• Study on Intra Domain Connection of RAN Nodes to Multiple CN Nodes
• Study on IMS Evolution
• Study on enhancements to IMS border functions for IMS Interconnection of services

I will add some details as I have the information and as I get time :)

Stage 2 Specification For Voice Over LTE from VOLGA Forum now available

From our friend Martin Sauter's blog:

Regular readers of this blog probably remember that I'm a fan of Voice over LTE via GAN (VOLGA). For those who don't, have a look here on more details on why I think it has a good chance of becoming THE voice solution for LTE. It's amazing how fast the Volga-Forum is pushing out the specifications. In May, they published the stage 1 specification document, which contains a high level architecture and the requirements. Now only a month later, a first version of the stage 2 specification is available. Stage 2 specifications as per 3GPP contain a detailed architecture description and all procedures required from connecting to the network, originating and terminating calls, doing handovers, etc.

While their speed is incredible, maybe it should not be that surprising, because VOLGA is based on the already existing 3GPP GAN (Generic Access Network, i.e. GSM over Wi-Fi) specification. That's a good thing because that means that VOLGA could thus be developed quite quickly as it's likely that existing products can be modified instead of being designed from scratch. In addition, this should also mean that the first version of the standard is already quite mature as many areas were already verified during implementation and rollout of GAN in current networks.

I did a quick comparison between the two stage 2 specs and as I expected, many parts are very similar. While the GAN stage 2 specification has 126 pages, the current VOLGA stage 2 specification has 87 pages. This is probably because VOLGA is simpler than GAN. There are fewer handover procedures and most of the handover details are part of the 3GPP Single Radio Voice Call Continuity (SR-VCC) specification (for IMS) so they don't have to be included in the VOLGA spec. In addition to fewer handover scenarios, handovers are a bit more simple with LTE from a VOLGA perspective, as the network takes care of it unlike with GAN, where the mobile has to force the network into a handover. Also, there's no need to support the packet switched part of the network which also significantly lowers the complexity.

Well done, I am looking forward to the stage 3 specification which will contain the details on all messages and information elements used.

I blogged about VoLGA last month here.

LTE and 4G IPR

The other day I heard from Alex GeunHo Lee about his new blog related to 4G technologies IPR. Alex has got extensive experience in IPR and patent related issues and I am sure his blog will be very useful for everyone.

Couple of Alex's presentations are embedded below which I am sure many would find interesting.

LTE Essential Patents Landscape 2009 2Q

4G Key Technologies Patent Landscape 2Q 2009