Over the last year or so, I have heard quite a few discussions and read many articles around why QUIC is so good and why we will replace TCP with QUIC (Quick UDP Internet Connection). One such article talking about QUIC benefits says:
QUIC was initially developed by Google as an alternative transport protocol to shorten the time it takes to set up a connection. Google wanted to take benefits of the work done with SPDY, another protocol developed by Google that became the basis for the HTTP/2 standard, into a transport protocol with faster connection setup time and built-in security. HTTP/2 over TCP multiplexes and pipelines requests over one connection but a single packet loss and retransmission packet causes Head-of-Line Blocking (HOLB) for the resources that were being downloaded in parallel. QUIC overcomes the shortcomings of multiplexed streams by removing HOLB. QUIC was created with HTTP/2 as the primary application protocol and optimizes HTTP/2 semantics.
What makes QUIC interesting is that it is built on top of UDP rather than TCP. As such, the time to get a secure connection running is shorter using QUIC because packet loss in a particular stream does not affect the other streams on the connection. This results in successfully retrieving multiple objects in parallel, even when some packets are lost on a different stream. Since QUIC is implemented in the userspace compared to TCP, which is implemented in the kernel, QUIC allows developers the flexibility of improving congestion control over time, since it can be optimized and better replaced compared to kernel upgrades (for example, apps and browsers update more often than OS updates).
Georg Mayer mentioned about QUIC in a recent discussion with Telecom TV. His interview is embedded below. Jump to 5:25 for QUIC part only
Prof. Andy Sutton, Principal Network Architect, Architecture & Strategy, TSO, BT, provided an update on 5G Network Architecture & Design last year which was also the most popular post of 2017 on 3G4G blog. This year again, he has delivered an update on the same topic at IET '5G - State of Play' conference. He has kindly shared the slides (embedded below) that are available to download from Slideshare.
There are many valuable insights in this talk and the other talks from this conference. All the videos from the IET conference are available here and they are worth your time.
Its been a year since I last posted about Augmented / Virtual Reality Requirements for 5G. The topic of Virtual Reality has since made good progress for 5G. There are 2 technical reports that is looking at VR specifically. They are:
Anyway, back in Dec. 3GPP and Virtual Reality Industry Forum (VRIF) held a workshop on VR Ecosystem & Standards. All the materials, including agenda is available here. The final report is not there yet but I assume that there will be a press release when the report is published.
While there are some interesting presentations, here is what I found interesting:
From presentation by Gordon Castle, Head of Strategy Development, Ericsson
From presentation by Martin Renschler, Senior Director Technology, Qualcomm
For anyone wanting to learn more about 6 degrees of freedom (6- DoF), see this Wikipedia entry. According to the Nokia presentation, Facebook’s marketing people call this “6DOF;” the engineers at MPEG call it “3DOF+.”
XR is 'cross reality', which is any hardware that combines aspects of AR, MR and VR; such as Google Tango.
From presentation by Devon Copley, Former Head of Product, Nokia Ozo VR Platform
Some good stuff in the pres.
From presentation by Youngkwon Lim, Samsung Research America; the presentation provided a link to a recent YouTube video on this presentation. I really liked it so I am embedding that here:
Finally, from presentation by Gilles Teniou, SA4 Vice chairman - Video SWG chairman, 3GPP
You can check and download all the presentations here.
Satellites has been an area of interest of mine for a while as some of you know that I used to work as Satellite Applications & Services Programme manager at techUK. I have written about how I see satellites complementing the mobile networks here and here.
Its good to see that there is some activity in 3GPP going on about satellites & Non-terrestrial networks (NTN) in 5G. While there are some obvious roles that satellites can play (see pic above), the 5G work is looking to cover a lot more topics in details.
3GPP TR 38.913: Study on scenarios and requirements for next generation access technologies looks at 12 different scenarios, the ones relevant to this topic ate Air to ground, Light aircraft and Satellite to terrestrial.
3GPP TR 38.811: Study on New Radio (NR) to support non terrestrial networks (Release 15) covers this topic a bit more in detail. From looking at how satellites and other aerial networks work in general, it looks at the different NTN architecture options as can be seen above.
People looking to study this area in detail should probably start looking at this TR first.
3GPP also released a news item on this topic last week. It also refers to the above TR and a new one for Release 16. The following from 3GPP news:
The roles and benefits of satellites in 5G have been studied in 3GPP Release 14, leading to the specific requirement to support satellite access being captured in TS 22.261 - “Service requirements for next generation new services and markets; Stage 1”, recognizing the added value that satellite coverage brings, as part of the mix of access technologies for 5G, especially for mission critical and industrial applications where ubiquitous coverage is crucial. Satellites refer to Spaceborne vehicles in Low Earth Orbits (LEO), Medium Earth Orbits (MEO), Geostationary Earth Orbit (GEO) or in Highly Elliptical Orbits (HEO). Beyond satellites, Non-terrestrial networks (NTN) refer to networks, or segments of networks, using an airborne or spaceborne vehicle for transmission. Airborne vehicles refer to High Altitude Platforms (HAPs) encompassing Unmanned Aircraft Systems (UAS) - including tethered UAS, Lighter than Air UAS and Heavier than Air UAS - all operating at altitude; typically between 8 and 50 km, quasi-stationary. These Non-terrestrial networks feature in TSG RAN’s TR 38.811 “Study on NR to support non-terrestrial networks”. They will:
Help foster the 5G service roll out in un-served or underserved areas to upgrade the performance of terrestrial networks
Reinforce service reliability by providing service continuity for user equipment or for moving platforms (e.g. passenger vehicles-aircraft, ships, high speed trains, buses)
Increase service availability everywhere; especially for critical communications, future railway/maritime/aeronautical communications
Enable 5G network scalability through the provision of efficient multicast/broadcast resources for data delivery towards the network edges or even directly to the user equipment
The objective of TR 38.811 is to study channel models, to define the deployment scenarios as well as the related system parameters and to identify and assess potential key impact areas on the NR. In a second phase, solutions for the identified key impacts on RAN protocols/architecture will be evaluated and defined. A second study item, the “Study on using Satellite Access in 5G” is being addressed in Working Group SA1. It shall lead to the delivery of the corresponding Technical Report TR 22.822 as part of Release 16. This study will identify use cases for the provision of services when considering the integration of 5G satellite-based access components in the 5G system. When addressing the integration of (a) satellite component(s), use cases will identify new potential requirements for 5G systems addressing:
The associated identification of existing / planned services and the corresponding modified or new requirements
The associated identification of new services and the corresponding requirements
The requirements on set-up / configuration / maintenance of the features of UE’s when using satellite components related features as well for other components from the 5G system
Regulatory requirements when moving to (or from) satellite from (or to) terrestrial networks
I recently did a small presentation on 3GPP Security, looking at the how the security mechanism works in mobile cellular networks; focusing mainly on signaling associated with authentication, integrity protection and ciphering / confidentiality. Its targeted towards people with basic understanding of mobile networks. Slides with embedded video below.
As you can see, 7/10 were on 5G which is probably not a surprise 😉.
In other news, this year I have done a lot more activities on 3G4G sites (thanks to support and encouragement from my current employer, Parallel Wireless). You can see links to all different 3G4G channels on top of the blog. I was also interviewed by TechPlayon and TechTrained (the similarity of name is just a coincidence). I was also named a key 5G influencer for 2017.
Back in 2011, I wrote the 1000th post and asked for your feedback. Here again, I would like to ask for your feedback, either on this post or on any posts. There are check-boxes for you to give instant feedback or you can add your comments in any of the posts.
I also mentioned in 2011 that the 3G4G blog will be touching 1.5 million page view mark, now in 2017 (10 years after the start of this blog), we have crossed over 9.5 million official page views (page views for first 3 years were not counted). Here is a snapshot of the stats for this and the small cells blog.
This has all been possible because of contributions from many individuals who share their presentations, knowledge and support my activities in many different ways. Thank you!
Finally, I can make mistakes too so please feel free to correct me anytime you spot me saying something wrong. I don't mind 😊
While going through the latest issue of CW Journal, I came across this article from Moray Rumney, Lead Technologist, Keysight. It highlights an interesting point that I missed out earlier that 5G also includes all LTE specifications from Release 15 onwards.
I reached out to our CW resident 3GPP standards expert Sylvia Lu to clarify and received more details.
There is a whole lot of detail available in RP-172789.zip. Here RIT stands for Radio Interface Technology and SRIT for Set of RIT.
Indeed, NB-IoT and Cat-M will also be part of the initial IMT-2020 submissions early next year.. watch the space
In fact at Sylvia clarified, NB-IoT and Cat-M will also be part of the initial IMT-2020 submissions early next year. Thanks Sylvia.
There is also this nice presentation by Huawei in ITU (here) that describes Requirements, Evaluation Criteria and Submission Templates for the development of IMT-2020. It is very helpful in understanding the process.
Coming back to the question I have often asked (see here for example),
1. What features are needed for operator to say they have deployed 5G, and
2. How many sites / coverage area needed to claim 5G rollout
With LTE Release-15 being part of 5G, I think it has just become easy for operators to claim they have 5G.
One of the items in 3GPP Rel-14 is Control and User Plane Separation of EPC nodes (CUPS). I have made a video explaining this concept that is embedded below.
In 3G networks (just considering PS domain), the SGSN and GGSN handles the control plane that is responsible for signalling as well as the user plane which is responsible for the user data. This is not a very efficient approach for deployment.
You can have networks that have a lot of signalling (remember signaling storm?) due to a lot of smartphone users but not necessarily consuming a lot of data (mainly due to price reasons). On the other hand you can have networks where there is not a lot of signalling but lot of data consumption. An example of this would be lots of data dongles or MiFi devices where users are also consuming a lot of data, because it’s cheap.
To cater for these different scenarios, the control plane and user plane was separated to an extent in the Evolved Packet Core (EPC). MME handles the control plane signalling while S-GW & P-GW handles the user plane
CUPS goes one step further by separating control & user plane from S-GW, P-GW & TDF. TDF is Traffic Detection Function which was introduced together with Sd reference point as means for traffic management in the Release 11. The Sd reference point is used for Deep Packet Inspections (DPI) purposes. TDF also provides the operators with the opportunity to capitalize on analytics for traffic optimization, charging and content manipulation and it works very closely with Policy and charging rules function, PCRF.
As mentioned, CUPS provides the architecture enhancements for the separation of S-GW, P-GW & TDF functionality in the EPC. This enables flexible network deployment and operation, by using either distributed or centralized deployment. It also allows independent scaling between control plane and user plane functions - while not affecting the functionality of the existing nodes subject to this split.
Reducing Latency on application service, e.g. by selecting User plane nodes which are closer to the RAN or more appropriate for the intended UE usage type without increasing the number of control plane nodes.
Supporting Increase of Data Traffic, by enabling to add user plane nodes without changing the number of SGW-C, PGW-C and TDF-C in the network.
Locating and Scaling the CP and UP resources of the EPC nodes independently.
Independent evolution of the CP and UP functions.
Enabling Software Defined Networking to deliver user plane data more efficiently.
The following high-level principles were also adopted for the CUPS:
The CP function terminates the Control Plane protocols: GTP-C, Diameter (Gx, Gy, Gz).
A CP function can interface multiple UP functions, and a UP function can be shared by multiple CP functions.
An UE is served by a single SGW-CP but multiple SGW-UPs can be selected for different PDN connections. A user plane data packet may traverse multiple UP functions.
The CP function controls the processing of the packets in the UP function by provisioning a set of rules in Sx sessions, i.e. Packet Detection Rules for packets inspection, Forwarding Action Rules for packets handling (e.g. forward, duplicate, buffer, drop), Qos Enforcement Rules to enforce QoS policing on the packets, Usage Reporting Rules for measuring the traffic usage.
All the 3GPP features impacting the UP function (PCC, Charging, Lawful Interception, etc) are supported, while the UP function is designed as much as possible 3GPP agnostic. For example, the UPF is not aware of bearer concept.
Charging and Usage Monitoring are supported by instructing the UP function to measure and report traffic usage, using Usage Reporting Rule(s). No impact is expected to OFCS, OCS and the PCRF.
The CP or UP function is responsible for GTP-u F-TEID allocation.
A legacy SGW, PGW and TDF can be replaced by a split node without effecting connected legacy nodes.
CUPS forms the basis of EPC architecture evolution for Service-Based Architecture for 5G Core Networks. More in another post soon.
A short video on CUPS below, slides available here.
