Showing posts with label Release 12. Show all posts
Showing posts with label Release 12. Show all posts

Sunday, 10 November 2013

SIPTO Evolution


Couple of years back I did a post on SIPTO (Selected IP Traffic Offload) and related technologies coming as part of Rel-10. I also put up a comparison for SIPTO, LIPA and IFOM here. Having left it for couple of years, I found that there have been some enhancements to the architecture from the basic one described here.

I have embedded the NEC paper below for someone wanting to investigate further the different options shown in the picture above. I think that even though the operator may offload certain type of traffic locally, they would still consider that data as part of the bundle and would like to charge for it. At the same time there would be a requirement on the operator for lawful interception, so not sure how this will be managed for different architectures. Anyway, feel free to leave comments if you have any additional info.



Tuesday, 29 October 2013

ANDSF: Evolution and Roaming with Hotspot 2.0


Access Network Discovery and Selection Function (ANDSF) is still evolving and with the introduction of Hotspot 2.0 (HS 2), there is a good possibility to provide seamless roaming from Cellular to Wi-Fi, Wi-Fi to Wi-Fi and Wi-Fi to Cellular.


There is a good paper (not very recent) by Alcatel-Lucent and BT that explains these roaming scenarios and other ANDSF policies related information very well. Its embedded below:




Sunday, 27 October 2013

TDD-FDD Joint CA


From a recent NTT Docomo presentation (embedded below). Whereas right now 3GPP has only been working on FDD or TDD scenarios, this proposal is a combination of FDD as P-Cell and TDD as S-Cell. Inter-Technology carrier aggregation is another possible option. Anyway, the complete presentation is below.


LTE-Advanced Enhancements and Future Radio Access Toward 2020 and Beyond from Zahid Ghadialy

Updated on 29/10/2013

3GPP has already started working on this work item. See RP-131399 for details.

Friday, 11 October 2013

3GPP Rel-12 SON Status


Considering how popular the Release-11 SON post have been, here is Rel-12 status that was presented in the SON Conference in October 2013. Complete presentation embedded below:



You may also be interested in reading a comprehensive report prepared by David Chambers here.

Wednesday, 21 August 2013

eIMTA: Enhanced Interference Mitigation & Traffic Adaptation


eIMTA is one of the features being discussed in 3GPP Rel-12. The pictures above and below provide the details.
As can be seen, at the moment all the eNodeB's associated with a network has to transmit the same UL/DL pattern throughout out the system. With eIMTA, each eNodeB can decide the UL/DL pattern itself depending on the load.
The main challenge would be interference management while using this scheme.

See also, this slideshare presentation for details:


Friday, 2 August 2013

Mobile Relay Nodes (MRN) in Rel-12


Interesting article in IEEE Comms Magazine (embedded below) about the Moving Relay Node (MRN). 3GPP has done a study on a similar topic available in 3GPP TR 36.836. To make the case for the MRN they provide a reference scenario of high speed train

The TGV Eurostar in Europe is 393 m long, moves at speed reaching 300 km/h. The Shinkansen in Japan has similar characteristics, with 480 m long, 300 km/h of commercial speed. The high speed train in China is 432 m long moving at speed reaching 350 km/h.

Due to fast moving and well shield carriage, the network in high speed train scenario faces severe Doppler frequency shift and high penetration loss, reduced handover success rate and increased power consumption of UEs.


To improve the coverage of the train deployment, access devices can be mounted on the high speed train, providing a wireless backhaul connection via the eNBs along the railway by outer antenna e.g. installed on top of the train, and wireless connectivity to the UEs inside carriages by inner antenna installed inside.

MRN is a good solution but when it has to operate alongside with many other technologies can pose challenges. The IEEE article summarises it as follows:

Furthermore, new challenges regarding interference management arise due to the use of MRNs. As the distance between an MRN and the vehicular UE served by it is very short, the MRN and the vehicular UE can communicate with each other using very low power. In addition, the VPL can further help to dampen the signal of the MRN access link that propagates out from the vehicle. Thus, compared to direct transmission, the use of MRNs generates less interference from the access link, for both downlink and uplink, to UE outside the vehicles. This is appreciated in a densely deployed urban scenario where link availabilities are usually dependent on interference rather than coverage. For the backhaul link, however, the problem becomes complicated, as interference is expected both between different MRN backhaul links, and between MRN backhaul links and macro UE. The use of predictor antennas can improve CSI accuracy to enable the use of advanced interference avoidance and cancellation schemes for the backhaul links. Nevertheless, whether enhancements on the current intercell interference coordination (ICIC) framework in LTE are needed to support the use of MRNs still requires further investigation.

I have been thinking of possible use of 8x8 MIMO, this can be one possible scenario where the network may use 8x8 or even 4x4. Anyway, the complete article is embedded below:




Wednesday, 31 July 2013

Making LTE fit for the IoT

Another presentation from the #FWIC2013. This presentation by Vodafone covers some of the areas where the LTE standards are being tweaked for making M2M work with them without issues.


Another area is the access barring that I have blogged about before here. This will become important when we have loads of devices trying to access the network at the same time.

The presentation is embedded below and you can also listen to the audio here.


Monday, 24 June 2013

3 Band Carrier Aggregation in Release-12


So it looks like in the latest 3GPP RAN meeting finally more than 2 carriers have been proposed for Carrier Aggregation. The TDoclist has a few items on 3 carriers for CA. In some cases its been specified that there is 1 uplink component carrier (1UL CC) but in other cases its not specified and I have not looked into details. Its good to finally see more than 2 carriers being discussed.

Rohde&Schwarz have explained in one of their whitepapers about the numbering of CA bands.

Now there is a possibility that we may have 2 contiguous bands and 1 band from an Inter-band so the naming would be accordingly. There are also going to be new carrier types (NCT), Band 29 for example. See details here.

Finally, If you want to learn more about Carrier Aggregation (CA) or other LTE-Advanced features, my article from last year, here, would be useful.

Friday, 7 June 2013

3GPP Public Safety focus in Rel-12


Public Safety is still a hot topic in the standards discussion and on this blog as well. Two recent posts containing presentations have been viewed and downloaded like hotcakes. See here and here.

3GPP presented on this topic in the Critical Communications World that took place last month. The following is from the 3GPP press release:

The ’Critical Communications World’ conference, held recently in Paris, has focused largely on the case for LTE standardized equipment to bring broadband access to professional users, by meeting their high demands for reliability and resilience.
Balazs Bertenyi, the 3GPP SA Chair, reported on the latest status of the first 3GPP features for public safety, in particular those covering Proximity services (Direct mode) and Group call. He spoke of the need to strike a balance between more or less customisation, to make use of commercial products while meeting the specific requirements for Public Protection and Disaster Relief (PPDR).
To ensure that these needs are met, Balazs Bertenyi called for the wholehearted participation of the critical communications community in 3GPP groups, by sending the right people to address the technical questions and obstacles that arise during the creation of work items.

A presentation and video from that event is embedded below:




For more details see here.

Monday, 3 June 2013

New Carrier Type (NCT) in Release-12 and Band 29

One of the changes being worked on and is already available in Release-11 is the Band 29. Band 29 is a special FDD band which only has a downlink component and no uplink component. The intention is that this band is available an an SCell (Secondary cell) in CA (Carrier Aggregation). 

What this means is that if this is only available as an SCell, any UE that is pre-Rel-11 should not try to use this band. It should not read the system information, reference information, etc. In fact the System Information serves little or no purpose as in CA, the PCell will provide the necessary information for this SCell when adding it using the RRC Reconfiguration message. This gives rise to what 3GPP terms as New Carrier Type for LTE as defined here. An IEEE paper published not long back is embedded below that also describes this feature in detail. 

The main thing to note from the IEEE paper is what they have shown as the unnecessary information being removed to make the carrier lean.

China Mobile, in their Rel-12 workshop presentation, have suggested 3 different types/possibilities for the NCT for what they call as LTE-Hi (Hi = Hotspot and Indoor).

Ericsson, in their Rel-12 whitepaper mention the following with regards to NCT:

Network energy efficiency is to a large extent an implementation issue. However, specific features of the LTE technical specifications may improve energy efficiency. This is especially true for higher-power macro sites, where a substantial part of the energy consumption of the cell site is directly or indirectly caused by the power amplifier.

The energy consumption of the power amplifiers currently available is far from proportional to the power-amplifier output power. On the contrary, the power amplifier consumes a non-negligible amount of energy even at low output power, for example when only limited control signaling is being transmitted within an “empty” cell.

Minimizing the transmission activity of such “always-on” signals is essential, as it allows base stations to turn off transmission circuitry when there is no data to transmit. Eliminating unnecessary transmissions also reduces interference, leading to improved data rates at low to medium load in both homogeneous as well as heterogeneous deployments.

A new carrier type is considered for Release 12 to address these issues. Part of the design has already taken place within 3GPP, with transmission of cell-specific reference signals being removed in four out of five sub frames. Network energy consumption can be further improved by enhancements to idle-mode support.

The IEEE paper I mentioned above is as follows:



Wednesday, 1 May 2013

Video: Quick summary of 3GPP Release 12 features

Ericsson recently posted a very good summary video of Release-12 features. My comments and more details are posted below the video:


You may have noticed that LTE Release 12 is also referred to as LTE-B as I posted in my blog post here. Unfortunately, this terminology is not supported by 3GPP which refers to all advancements of LTE as LTE-A. See comment on the post I just referred.

The Elevation Beamforming is also referred to as 3D-Beamforming or 3D-MIMO as I show here.

I havent written any posts on Dual connectivity and not exactly sure how it works but there is an interesting presentation on the Small Cells Enhancements in Release-12 on my blog here.

You can learn more about the WiFi and EPC Integration here.

Click on the following Direct Communications, Device to device (D2D) and Public Safety for more information on the topics.

There are many good presentations on Machine Type Communications (MTC) or M2M that are available on this label here.

Finally, I havent seen much about the lean carrier but now that I know, will add some information on this topic soon.

Related links:

Monday, 1 April 2013

The 'Phantom Cell' concept in LTE-B


One of the LTE-B proposals by NTT Docomo is this 'Phantom Cell' concept. A recent article from the IEEE Communications Magazine expands this further:


Phantom Cell Concept — In the current deployments, there are a number of capacity solutions for indoor environments such as WiFi, femtocells, and in-building cells using distributed antenna systems (DAS). However, there is a lack of capacity solutions for high-traffic outdoor environments that can also support good mobility and connectivity. Thus, we propose the concept of macro-assisted small cells, called the Phantom Cell, as a capacity solution that offers good mobility support while capitalizing on the existing LTE network. In the Phantom Cell concept, the C-plane/U-plane are split as shown in Fig. The C-plane of UE in small cells is provided by a macrocell in a lower frequency band, while for UE in macrocells both the C-plane and U-plane are provided by the serving macrocell in the same way as in the conventional system. On the other hand, the Uplane of UE in small cells is provided by a small cell using a higher frequency band. Hence, these macro-assisted small cells are called Phantom Cells as they are intended to transmit UE-specific signals only, and the radio resource control (RRC) connection procedures between the UE and the Phantom Cell, such as channel establishment and release, are managed by the macrocell.

The Phantom Cells are not conventional cells in the sense that they are not configured with cell specific signals and channels such as cell-ID-specific synchronization signals, cell-specific reference signals (CRS), and broadcast system information. Their visibility to the UE relies on macrocell signaling. The Phantom Cell concept comes with a range of benefits. One important benefit of macro assistance of small cells is that control signaling due to frequent handover between small cells and macrocells and among small cells can be significantly reduced, and connectivity can be maintained even when using small cells and higher frequency bands. In addition, by applying the new carrier type (NCT) that contains no or reduced legacy cell-specific signals, the Phantom Cell is able to provide further benefits such as efficient energy savings, lower interference and hence higher spectral efficiency, and reduction in cellplanning effort for dense small cell deployments.

To establish a network architecture that supports the C/U-plane split, and interworking between the macrocell and Phantom Cell is required. A straightforward solution to achieve this is to support Phantom Cells by using remote radio heads (RRHs) belonging to a single macro eNB. This approach can be referred to as intra-eNB carrier aggregation (CA) using RRHs. However, such a tight CA-based architecture has some drawbacks as it requires single-node operation with low-latency connections (e.g., optical fibers) between the macro and Phantom Cells. Therefore, more flexible network architectures should be investigated to allow for relaxed backhaul requirements between macro and Phantom Cells and to support a distributed node deployment with separated network nodes for each (i.e., inter-eNB CA).


Thursday, 14 March 2013

What is WebRTC and where does it fit with LTE and IMS

This simple video from MWC should give an idea on what WebRTC is and can do:


So what exactly WebRTC is in technical terms. Here is a recent presentation from WebRTC Conference and Expo



And here is another presentation that explains where it fits in with the LTE Architecture.



Dean Bubley from Disruptive Analysis has writted extensively on this topic and his recent post "Is the telephony "threat" from VoIP & WebRTC about competition or contextualisation?" is an interesting read.

Iain Sharp from Netovate recently pointed out that 3GPP have 'nearly' approved a work item for WebRTC access to IMS.

It would be interesting to see how operators will view WebRTC. As an opportunity or as a threat. Please feel free to air your opinions via comments.

Wednesday, 27 February 2013

Wi-Fi & Packet Core (EPC) Integration

Yesterday I wrote a blog post on whether Wi-Fi is the third RAN in the Metrocells blog. Today I am posting this excellent presentation that details how this Wi-Fi integration with EPC will be done.



Thursday, 14 February 2013

Scalable UMTS (S-UMTS) to accelerate GSM Refarming


Looks like a good idea from LTE will possibly be applied to UMTS/HSPA and it will also help accelerate the re-farming of GSM spectrum. A recent presentation from Qualcomm below:



Available to download from here.

Monday, 11 February 2013

Revisiting Coordinated Multi-point (CoMP) Technology

Looks like I re-visit CoMP every Q1 of the year. Couple of years back, I had posted a primer on CoMP here and last year I had a slide on schemes and deployments here. With Release-11 out of the door and  Release-12 getting in full swing in the standards, its time to re-visit this topic in a bit more detail. There are couple of presentations, one completely devoted to this topic and one that has a section on it. Both of them can be downloaded from slideshare.


Thursday, 31 January 2013

Monday, 28 January 2013

Overview of 3GPP Release-12 Study Item UPCON

Mobile operators are seeing significant increases in user data traffic. For some operators, user data traffic has more than doubled annually for several years. Although the data capacity of networks has increased significantly, the observed increase in user traffic continues to outpace the growth in capacity. This is resulting in increased network congestion and in degraded user service experience. Reasons for this growth in traffic are the rapidly increasing use of smart phones and tablet like devices, and the proliferation of data applications that they support, as well as the use of USB modem dongles for laptops to provide mobile Internet access using 3GPP networks. As the penetration of these terminals increases worldwide and the interest in content-rich multi-media services (e.g. OTT video streaming services) rises, this trend of rapidly increasing data traffic is expected to continue and accelerate.


Here are couple of presentations on this topic:







Related blog posts: