Wednesday 30 November 2011

Reducing CSFB Timing with RRC R9 Optimisations

While in the initial testing CSFB timing used to be between 6-8 seconds, most Rel-8 phones can complete the CSFB procedure between 4-4.5 seconds. Unfortunately this is still a lot in terms of signalling. To reduce this in Rel-9 there is a simple optimisation that has been done.
In the RRC Connection Release message, there is a possibility to add UTRAN/GERAN System Information messages. In the picture above, I have only shown UTRA System Information but a similar picture can be drawn for GERAN.

Once all the Mandatory SIB's are sent to the UE then it can immediately camp on without the need to read any other additional system info. This will reduce the CSFB time between 1-2 seconds.

The lesser the CSFB time, the better the Quality of end user experience

Tuesday 29 November 2011

Nice Pie Chart on different Android Devices

Click to enlarge

I guess Pie charts like these can convey more information then writing about the percentages of devices sold. Maybe we should use them more often to represent information.

Source: From a presentation by Deutsche Bank in the 4th LTE North America Conference, 8 - 9 November 2011, Dallas, Texas, USA

Saturday 26 November 2011

LTE Capacity Analysis

From the 4th LTE North America Conference, 8 - 9 November 2011, Dallas, Texas, USA
Presented by Bill Ingram, Cricket Communications, November 8, 2011

Wednesday 23 November 2011

Secure Wi-Fi for Large Scale Events and Arenas

Interesting presentation from Logica on Secure WiFi. The resolution of this presentation is low for security reasons as well, I guess.
To download this presentation and other presentation from the recent event, click here.

Monday 21 November 2011

HSDPA multiflow data transmission

From RP-111375:

HSPA based mobile internet offerings are becoming very popular and data usage is increasing rapidly. As a result, HSPA has begun to be deployed on more than one transmit antenna and/or on more than one carrier. As an example, the single cell downlink MIMO (MIMO-Physical layer) feature was introduced in Release 7. This feature allowed a NodeB to transmit two transport blocks to a single UE from the same cell on a pair of transmit antennas thus improving data rates at high geometries and providing a beamforming advantage to the UE in low geometry conditions. Subsequently, in Release-8 and Release-9, the dual cell HSDPA (DC-HSDPA) and dual band DC-HSDPA features were introduced. Both these features allow the NodeB to serve one or more users by simultaneous operation of HSDPA on two different carrier frequencies in two geographically overlapping cells, thus improving the user experience across the entire cell coverage area.

When a UE falls into the softer or soft handover coverage region of two cells on the same carrier frequency, the link from the serving HS-DSCH cell is capacity or coverage limited and the non-serving cell in its active set has available resources, it would be beneficial to schedule packets to this UE also from the non-serving cell and thereby improve this particular user’s experience.

One family of such schemes parses the incoming data for the user into multiple (restricted to two cells in the study) data streams or flows, each of which is transmitted from a different cell [8] Concurrent transmission of data from the two cells may either be permitted or the UE may be restricted to receiving data from only one cell during a given TTI. The former type of scheme is designated an aggregation scheme while the latter is termed a switching scheme. The aggregation scheme can be seen as subsuming the switching scheme at the network when scheduling to the user is restricted to the cell with better channel quality.

Figure 14 illustrates the basic multi-flow concept with both cells operating on the same carrier frequency F1.

3GPP studied different multipoint transmission options for HSDPA and documented the findings and performance gains in TR25.872 providing feasibility and performance justification for the specification work.

For more details also see:
See also old blog post on Multipoint HSDPA/HSPA here.

Sunday 20 November 2011

Do we need Fiber?

Click on the image to view full size

From a presentation by Acreo, available here.

Friday 18 November 2011

Interoperability between LTE FDD/TDD network

In countries where FDD and TDD are both in use, it would be interesting to see Dual-mode LTE terminals that would support both TDD and FDD and it should be possible to do a reselection as well has handovers from one mode to another.

It should be noted that the Structure of TDD and FDD frames are different as shown above.

If you are wondering why we need both FDD and TDD modes in the same geographical location, its because of Spectrum being available as well as with TDD allows possibility of different UL/DL data rates which generally means more efficient use of spectrum.

Thursday 17 November 2011

Shared Data plans anyone?

Shared plans are common in business tariffs but for some reason operators are reluctant to offer them on personal plans. With multiple devices becoming a common place, I would rather prefer to have a single plan that can be used across multiple devices rather than paying for a plan for each device.

From operator point of view, I think they would get a higher loyalty rate if they allow this as it means that if you want to change an operator, you would have to change SIM from multiple devices and some of these devices may be locked to an operator or may not work on other operators, etc.

An Infonetics Research report is embedded below:

Monday 14 November 2011

Overcapacity or Capacity Crunch?

A Qualcomm presentation from not too long back:
And another report from the UMTS Forum that is suggesting that the data traffic will grow 67 times from 2010 to 2020, summary embedded below:

Then I came across this interesting discussion on Twitter and a blog post by Dean Bubley in Disruptive Wireless blog.

Overcapacity has been summarised in few words as: Overcooked forecasts + WiFi offload + optimisation + LTE + more spectrum + caps/tiers + well-designed apps

In the blog post Dean's mentioned about the falling data usage that has been reported by O2. I would strongly recommend reading it.

From the network point of view, I think overcapacity is better for the time being as we are prepared for the short term future. In the long run, new devices and innovative apps may suddenly start driving up the data demand again and hopefully by that time we have sorted out some more of the capacity crunch issues.

What do you think?

Another concept phone from Nokia called 'HumanForm'

Description as follows:

HumanForm was created in a joint effort between Nokia Design and Nokia Research Center to translate the most promising new nanotechnologies into meaningful user experience, prototype those for decision making; and transfer and set aspiration for future portfolio.

Project is a key to bring significant user experience benefits to the market thereby creating mindshare and value share through nanotechnology enabled experiences.

HumanForm is a visionary solution for a dynamically flexible device beyond touch screen and voice communication where technology is invisible and intuition takes over. Natural interactions are enabled with kinetic user interface.

HumanForm concept and a follow-up Nokia Kinetic Device prototype were launched in Nokia World 2011.

To learn more, visit:

Sunday 13 November 2011

2nd Workshop by 3GPP and Broadband Forum

3GPP and Broadband Forum held another joint session recently. Here is the summary from that event (

All presentations and documents from that event is available to download and view here.

Saturday 12 November 2011

Video on the Vision of the Future

I came across couple of videos recently on how User Interface for the future is going to be different than what we are used to. Its already getting changed as we get used to the touch screens and gesture recognition. Here is the first video that came out couple of weeks back and has already had over 2 million hits:

There is a whole blog post dedicated to this which you may be interested in, available here.

Another one is on the gesture recognition that will probably make big on the future devices including TVs.

On a lighter note, the future generation would probably just take the touch and gesture recognition for granted. Here is one such video:

Wednesday 9 November 2011

Redirection, Reselection, Handovers and other Inter-RAT combinations in LTE

Another one from Qualcomm's 4G World presentation. You can see the number of scenarios that would have to be taken into account for; this was one of the reasons I believed SVLTE may be a good choice.

Related posts:

Tuesday 8 November 2011

Devices may require support for over 40 RF Bands to be used universally

Interesting picture from Qualcomm presentation in 4G World that shows that for Universal use, a device may have to support over 40 RF bands (which may not be physically possible and may also be overly expensive)

Related posts:

Monday 7 November 2011

Ericsson Video: Networked Society 'On the Brink'

In On The Brink we discuss the past, present and future of connectivity with a mix of people including David Rowan, chief editor of Wired UK; Caterina Fake, founder of Flickr; and Eric Wahlforss, the co-founder of Soundcloud. Each of the interviewees discusses the emerging opportunities being enabled by technology as we enter the Networked Society. Concepts such as borderless opportunities and creativity, new open business models, and today's 'dumb society' are brought up and discussed.

Saturday 5 November 2011

Three quick 3GPP Videos

Balazs Bertenyi, Dealing with the data explosion: Speaking about how 3GPP manages Releases and giving details of some of the key LTE features and some new work on the horizon.

Andrew Howell, GERAN and LTE Interworking: Andrew Howell, 3GPP GERAN Chairman, gives some background on the work of the GSM/EDGE RAN groups, including GELTE and the impact of machine type communications over legacy networks in the LTE age.

See also my earlier post on GELTE here.

Atle Monrad is Chairman of the 3GPP Core Network and Terminals group. In this short film, he explains the role of the protocol groups and gives a snap shot of the latest priorities for his group.

If you want to learn more about 3GPP, see earlier blog post here.

Thursday 3 November 2011

Femto as a Service (FaaS)

The following is from a recent Small Cells conference, presented by Colt Telecom.
I wanted to highlight the Femto as a Service (FaaS) concept as I think that this may be the way forward in future. Since multiple people have phones and devices from multiple operators and it would not be possible to have Femtocells from different operators, this may be an easy solution.

I am not exactly sure about what Spectrum would be used but I guess a better case could also have been that the Fixed operator has its own spectrum that it can use and a single Femto would allow any operator's device to connect. The Femto Core can route the call to the correct mobile operator so there would be no need for multiple femtos in a house.

Tuesday 1 November 2011

RRC Signalling in Rel-10 for MDT

Last year I wrote about Minimization of Drive Testing (MDT) and mentioned about the possibility of enhancements. Now looking at the new RRC specs I can see a new message LoggedMeasurementsConfiguration has been added,
When the UE is in RRC_CONNECTED mode, this message can be sent and the UE be informed about the measurements to be performed. The message contents are as follows:

LoggedMeasurementConfiguration-r10 ::= SEQUENCE {
criticalExtensions CHOICE {
loggedMeasurementConfiguration-r10 LoggedMeasurementConfiguration-r10-IEs,
spare3 NULL, spare2 NULL, spare1 NULL
criticalExtensionsFuture SEQUENCE {}

LoggedMeasurementConfiguration-r10-IEs ::= SEQUENCE {
traceReference-r10 TraceReference-r10,
traceRecordingSessionRef-r10 OCTET STRING (SIZE (2)),
tce-Id-r10 OCTET STRING (SIZE (1)),
absoluteTimeInfo-r10 AbsoluteTimeInfo-r10,
areaConfiguration-r10 AreaConfiguration-r10 OPTIONAL, -- Need OR
loggingDuration-r10 LoggingDuration-r10,
loggingInterval-r10 LoggingInterval-r10,
nonCriticalExtension SEQUENCE {} OPTIONAL -- Need OP

Once the UE has done the measurements, it can inform the network in one of the following messages, RRCConnectionSetupComplete, RRCConnectionReestablishmentComplete, RRCConnectionReconfigurationComplete and UEInformationResponse that it has the required information available. This is done by including the following new Enum:

logMeasAvailable-r10 ENUMERATED {true} OPTIONAL,

Finally, the network can request the logged Measurements information in the UE Information Request Message. The new fields for that are:

UEInformationRequest-v1020-IEs ::= SEQUENCE {
logMeasReportReq-r10 ENUMERATED {true} OPTIONAL,
nonCriticalExtension SEQUENCE {} OPTIONAL

The UE would send the following information in the response message:

LogMeasInfo-r10 ::= SEQUENCE {
locationInfo-r10 LocationInfo-r10 OPTIONAL,
relativeTimeStamp-r10 INTEGER (0..7200),
servCellIdentity-r10 CellGlobalIdEUTRA,
measResultServCell-r10 SEQUENCE {
rsrpResult-r10 RSRP-Range,
rsrqResult-r10 RSRQ-Range
measResultNeighCells-r10 SEQUENCE {
measResultListEUTRA-r10 MeasResultList2EUTRA-r9 OPTIONAL,
measResultListUTRA-r10 MeasResultList2UTRA-r9 OPTIONAL,
measResultListGERAN-r10 MeasResultList2GERAN-r10 OPTIONAL,
measResultListCDMA2000-r10 MeasResultList2CDMA2000-r9 OPTIONAL

MeasResultList2GERAN-r10 ::= SEQUENCE (SIZE (1..maxCellListGERAN)) OF MeasResultListGERAN

LocationInfo-r10 ::= SEQUENCE {
locationCoordinates-r10 CHOICE {
ellipsoid-Point-r10 OCTET STRING,
ellipsoidPointWithAltitude-r10 OCTET STRING,
horizontalVelocity-r10 OCTET STRING OPTIONAL,