Tuesday, 20 September 2011

Panel Session on Small Cells (Femtocells) from Cambridge Wireless SIG event

Panel Session on Small Cells (Femtocells) from Cambridge Wireless SIG event from Zahid Ghadialy on Vimeo.

From the Cambridge Wireless Small Cell Special Interest Group event


“Small Cells: the beginning and where we are now”

15 September 2011

At The IET, Savoy Place, London, WC2R 0BL


Panel Session

Chair: Mike Bowerman, Account Manager, Alcatel Lucent.

Participants (from Left to right):

Professor Will Stewart, IET

Houston Spencer, VP Solutions and Marketing, Alcatel-Lucent

Will Franks, CTO and Founder, Ubiquisys

Chris Cox, Director of Marketing, ip.access

More details about the speakers and the event available at: http://www.cambridgewireless.co.uk/Agenda/SCS1_15.09.11.pdf


Monday, 19 September 2011

Summary from the 'Small Cells' Event in Cambridge Wireless

We recently had our first 'Small Cells' SIG event in Cambridge Wireless entitled 'Small Cells: The beginning and where we are now'. The following presentation is the Introduction to Cambridge wireless and the 'Small Cells' SIG (special interest group).


Embedded below are the slides and the videos that were taken by our host for the day, 'The IET'.

The first presentation was by Prof. Will Stewart of The IET entitled 'Small Cells - Why small cells?'.



Next presentation: 'Small Cells - the big brother of femtocells. Why they are needed, and where is the femtocell market that they build on' by Will Franks, Ubiquisys



Next Presentation: 'Small Cells - On the origin of Small Cells by means of natural selection, or the preservation of favoured providers in the struggle for mobile broadband' by Houston Spencer, Alcatel-Lucent



Final Presentation: 'Small Cells - Mass scale femtocell deployments' by Chris Cox, IP.Access



Overall it was a good event. The main complaint was that people had lots of questions but didnt get to ask them. Hopefully they will ask them in the future events.

Wednesday, 14 September 2011

Inter-technology Carrier Aggregation

Another one from the 4G Americas whitepaper of Mobile Broadband explosion:

Carrier aggregation will play an important role in providing operators maximum flexibility for using all of their available spectrum. By combining spectrum blocks, LTE-Advanced will be able to deliver much higher throughputs than otherwise possible. Asymmetric aggregation (i.e., different amounts of spectrum used on the downlink versus the uplink) provides further flexibility and addresses the fact that currently there is greater demand on downlink traffic than uplink traffic. Specific types of aggregation include:

  • Intra-band on adjacent channels.
  • Intra-band on non-adjacent channels.
  • Inter-band (e.g., 700 MHz, 1.9 GHz).
  • Inter-technology (e.g., LTE on one channel, HSPA+ on another). This is currently a study item for Release 11. While theoretically promising, a considerable number of technical issues will have to be addressed.

Tuesday, 13 September 2011

CELL_FACH to LTE Mobility

At the moment, transition from RRC states from UMTS to LTE can happen from CELL_DCH to E-UTRA_RRC_CONNECTED state via Handover or from UTRA_IDLE to E-UTRA_RRC_IDLE via Cell Reselection. There is a study ongoing to transition from CELL_FACH to LTE. The state has not been specified but my guess is that it would probably be E-UTRA_RRC_CONNECTED. The following is the reasoning based on RP-111208:

It is our understanding that some of the Cell_FACH enhancement proposals for Release 11 are targeted to make it more attractive to keep UEs longer in the Cell_FACH state than is expected with pre-Rel-11 devices. This expectation that the UEs may stay longer in the Cell_FACH state is in turn motivating the mobility from Cell_FACH state to LTE proposal.

For instance, as the network can already today release the Cell_FACH UE’s RRC Connection with redirection, network may want to redirect UE to the correct RAT and frequency based on the UE measurement. Specifically if the network strategy is to keep the UEs long time in Cell_FACH state, it would make sense to provide the network the tools to manage the UEs’ mobility in that state. In addition, the needs for mobility to LTE are somewhat different from mobility to e.g. GERAN, as the former would be typically priority based while the latter would happen for coverage reasons. Thus, if introduced, the network controlled mobility from UMTS Cell_FACH would be specifically interesting for the UMTS to LTE case.


Will update once I have more info.

Monday, 12 September 2011

LTE Rollouts and Deployment Scenarios

According to GSA report, as of August 2011, 26 commercial LTE networks in 18 countries are already rolled out as below:
As of Aug. 2011, 237 operators in 85 countries are investing in LTE:

* 174 LTE network commitments in 64 countries
* 63 pre-commitment trials in 21 more countries
* 26 commercial LTE networks launched
* At least 93 LTE networks are expected to be in commercial service by end 2012

The following is from the 4G Americas whitepaper:

There are many different scenarios that operators will use to migrate from their current networks to future technologies such as LTE. Figure 10 presents various scenarios including operators who today are using CDMA2000, UMTS, GSM and WiMAX. For example, as shown in the first bar, a CMDA2000 operator in scenario A could defer LTE deployment to the longer term. In scenario B, in the medium term, the operator could deploy a combination of 1xRTT, EV-DO Rev A/B and LTE and, in the long term, could migrate EV-DO data traffic to LTE. In scenario C, a CDMA2000 operator with just 1xRTT could introduce LTE as a broadband service and, in the long term, could migrate 1xRTT users to LTE including voice service.


3GPP and 3GPP2 both have specified detailed migration options for current 3G systems (UMTS-HSPA and EV-DO) to LTE. Due to economies of scale for infrastructure and devices, 3GPP operators are likely to have a competitive cost advantage over Third Generation Partnership Project 2 (3GPP2) operators. One option for GSM operators that have not yet committed to UMTS, and do not have an immediate pressing need to do so, is to migrate directly from GSM/EDGE or Evolved EDGE to LTE with networks and devices supporting dual-mode GSM-EDGE/LTE operation.