Sunday, 29 May 2016

5G & 802.11ax

Samsung is one of the 5G pioneers who has been active in this area for quite a while, working in different technology areas but also making results and details available for others to appreciate and get an idea on what 5G is all about. 

I published a post back in 2014 from their trials going on then. Since then they have been improving on these results. They recently also published the 5G vision paper which is available here and here.

In the recent 5G Huddle, Raj Gawera from Samsung gave an excellent presentation (below) on the topic of "The future connected world". 

What we really liked is how closely 5G and 802.11ax can be considered aligned, not only in terms of requirements but also the roadmap.

Anyway, here is the presentation embedded below. Let me know what you think in the comments below.

Sunday, 22 May 2016

QCI Enhancements For Mission Critical Communications

Its been quite a while since I posted about QCI and end-to-end bearer QoS in EPC. In LTE Release-12 some new QCI values were added to handle mission critical communications.

This picture is taken from a new blog called Public Safety LTE. I have discussed about the Default and Dedicated bearers in an earlier post here (see comments in that post too). You will notice in the picture above that new QCI values 65, 66, 69 & 70 have been added. For mission critical group communications new default bearer 69 would be used for signalling and dedicated bearer 65 will be used for data. Mission critical data would also benefit by using QCI 70.

LTE for Public Safety that was published last year provides a good insight on this topic as follows:

The EPS provides IP connectivity between a UE and a packet data network external to the PLMN. This is referred to as PDN connectivity service. An EPS bearer uniquely identifies traffic flows that receive a common QoS treatment. It is the level of granularity for bearer level QoS control in the EPC/E-UTRAN. All traffic mapped to the same EPS bearer receives the same bearer level packet forwarding treatment. Providing different bearer level packet forwarding treatment requires separate EPS bearers.

An EPS bearer is referred to as a GBR bearer, if dedicated network resources related to a Guaranteed Bit Rate (GBR) are permanently allocated once the bearer is established or modified. Otherwise, an EPS bearer is referred to as a non-GBR bearer.

Each EPS bearer is associated with a QoS profile including the following data:
• QoS Class Identifier (QCI): A scalar pointing in the P-GW and eNodeB to node-specific parameters that control the bearer level packet forwarding treatment in this node.
• Allocation and Retention Priority (ARP): Contains information about the priority level, the pre-emption capability, and the pre-emption vulnerability. The primary purpose of the ARP is to decide whether a bearer establishment or modification request can be accepted or needs to be rejected due to resource limitations.
• GBR: The bit rate that can be expected to be provided by a GBR bearer.
• Maximum Bit Rate (MBR): Limits the bit rate that can be expected to be provided by a GBR bearer.

Following QoS parameters are applied to an aggregated set of EPS bearers and are part of user’s subscription data:
• APN Aggregate Maximum Bit Rate (APN-AMBR): Limits the aggregate bit rate that can be expected to be provided across all non-GBR bearers and across all PDN connections associated with the APN.
• UE Aggregate Maximum Bit Rate (UE-AMBR): Limits the aggregate bit rate that can be expected to be provided across all non-GBR bearers of a UE. The UE routes uplink packets to the different EPS bearers based on uplink packet filters assigned to the bearers while the P-GW routes downlink packets to the different EPS bearers based on downlink packet filters assigned to the bearers in the PDN connection.

Figure 1.5 above shows the nodes where QoS parameters are enforced in the EPS system.

Related links:

Saturday, 14 May 2016

4G / LTE by stealth

In the good old days when people used to have 2G phones, they were expensive but all people cared about is Voice & SMS.

The initial 3G phones were bulky/heavy with small battery life, not many apps and expensive. There was not much temptation to go and buy one of these, unless it was heavily subsidised by someone. Naturally it took a while before 3G adoption became common. In the meantime, people had to go out of their way to get a 3G phone.

With 4G, it was a different story. Once LTE was ready, the high end phones started adding 4G in their phones by default. What it meant was that if the operator enabled them to use 4G, these devices started using 4G rather than 3G. Other lower end devices soon followed suit. Nowadays, unless you are looking for a real cheap smartphone, your device will have basic LTE support, maybe not advanced featured like carrier aggregation.

The tweets below do not surprise me at all:

This is what I refer to as 4G or LTE by stealth.

Occasionally people show charts like these (just using this as a reference but not pin pointing anyone) to justify the 5G growth trajectory with 4G in mind. It will all depend on what 5G will mean, how the devices look like, what data models are on offer, what the device prices are like, etc.

I think its just too early to predict if there will be a 5G by stealth.

Monday, 2 May 2016

Does 5G need 'Next Generation' of Internet Protocols?

I have often heard Martin Geddes mention that the Internet is broken, the protocols (TCP/IP) are wrong and if we want to continue the way our data usage is going, we need to define new protocols (see here for example). It was good to find out last week at 5G Huddle that ETSI is already working on this.

The TCP/IP protocol suite has undoubtedly enabled the evolution of connected computing and many other developments since its invention during the 1970’s. Thanks to the development and ubiquity of this protocol stack, we have managed to build an Internet on which we are dependent as a communications tool, an information storage and distribution tool, a marketing channel and a sales and distribution platform, for consumers and for businesses large and small.

However, the industry has reached a point where forward leaps in the technology of the local access networks will not deliver their full potential unless, in parallel, the underlying protocol stacks used in core and access networks evolve. The development of future 5G systems presents a unique opportunity to address this issue, as a sub-optimal protocol architecture can negate the huge performance and capacity improvements planned for the radio access network.

ETSI has created an Industry Specification Group to work on Next Generation Protocols (NGP ISG), looking at evolving communications and networking protocols to provide the scale, security, mobility and ease of deployment required for the connected society of the 21st century.

The NGP ISG will identify the requirements for next generation protocols and network architectures, from all interested user and industry groups. Topics include:

  • Addressing
  • Security, Identity, Location, Authorization, Accounting/Auditing and Authentication
  • Mobility
  • Requirements from Internet of Things
  • Requirements from video and content distribution
  • Requirements from ultra‐low latency use cases from different sectors (i.e. automotive)
  • Requirements from network operators (e.g. challenges with E2E encrypted content)
  • Requirements from eCommerce
  • Requirements for increased energy efficiency within the global ICT sector.

This ISG is seen as a transitional group i.e. a vehicle for the 5G community (and others of interest) to first gather their thoughts and prepare the case for the Internet community’s engagement in a complementary and synchronised modernisation effort.

The ISG provides a forum for interested parties to contribute by sharing research and results from trials and developments in such a way that a wider audience can be informed. Other standards bodies will be involved so that parallel and concerted standardization action can take place as a further step in the most appropriate standards groups.

Andy Sutton, chair of the NGP recently gave the following presentation in 5G Huddle:

Please feel free to add your opinions in the comments.

Further reading:

**** Added 05/06/2016:20.00 ****
A whitepaper published by ETSI on this topic is available here and embedded below: