Showing posts with label Backhaul. Show all posts
Showing posts with label Backhaul. Show all posts

Friday, 31 January 2020

Prof. Andy Sutton: Backhauling the 5G Experience - Jan 2020


Prof. Andy Sutton has shared quite a few presentations and talks on this blog. His presentations from the annual 'The IET 5G Seminar' has made it to the top 10 for the last 3 years in a row. His talk from 2019, 2018 & 2017 is available for anyone interested.

The title of this year's conference was '5G 2020 - Unleashed'. The details are available here and the video of all the talks are here. As always, the slides and video is embedded below.

Slides



Video


There are a lot of bands that keep on getting mentioned, especially in relation to backhaul. Here is a summary of these bands that would come handy.



Related Posts:

Monday, 16 December 2019

5G Integrated Access and Backhaul (IAB) Enhancements in Rel-17


It's been a while since I last wrote about IAB on this blog here. At that time 3GPP Release-16 was being discussed. Since then things have moved on. While Release-16 is being prepared for final release soon, Release-17 study and work items have just been agreed upon.

IAB is included as part of Rel-16 but there isn't a comprehensive document or presentation easily available to details all that it will contain. Similarly the enhancements for Release-17 are available only superficially. Qualcomm is well known for making some really excellent presentations available on 5G. One of their presentations from January (here) has some details on IAB (pg. 32 - 35). There was also an excellent presentation by Navid Abedini, Qualcomm from IEEE Sarnoff Symposium, 2019 which is embedded at the end.


In a 3GPP RAN#84 discussion document RP-191181, Samsung has provided a comprehensive summary of what is being done as part of Rel-16 and what did not make in that:
  • Rel-16 IAB aims at basic operations
    • Architecture and protocol design
    • IAB integration procedure 
    • Routing, BAP and BH configuration
    • CP and UP data transmission  via IAB
    • Topology support: 
      • Spanning Tree (ST) and Directed acyclic graph (DAG) 
      • Intra-Donor adaptation is prioritized
  • The following cannot  be supported in Rel-16
    • Mobile IAB
    • Topology support: Mesh
  • Some functionalities in Rel-16 may not be completed due to time constrains e.g. 
    • Topology adaptation between IAB donors
    • Mechanisms for efficient control signaling transmission
Ericsson also provides a good summary in RP-190971 regarding Release 16 IAB and Rel-17 enhancements:
  • IAB Rel-16 provide basic support for multi-hop and multi-path relaying. 
  • The solution supports 
    • QoS prioritization of traffic on the backhaul link
    • Flexible resource usage between access and backhaul
    • Topology adaptivity in case link failure
  • In Rel-17 it would be possible to further evolve the IAB solution targeting increased efficiency and support for new use cases


Meanwhile in the recently concluded RAN#86, AT&T provided a good detailed summary on what enhancements are required for IAB as part of Rel-17 in RP-192709
  • Duplexing enhancements
    • Multiplexing beyond TDM (FDM/SDM/multi-panel Tx/Rx) including multi-parent scenarios, case 6/7 timing alignment, power control/CLI optimizations
  • Topology enhancements
    • Mobile IAB: CP/UP split + Group mobility 
    • Inter-CU topology adaptation
    • Mesh-connectivity between IAB nodes for local control/user plane routing
  • User plane enhancements
    • Multi-hop scheduling enhancement – exchange of benefit metric between IAB nodes to enable radio-aware multi-hop scheduling to improve throughput performance
  • Network Coding
    • Study benefits compared to duplication over redundant backhaul routes

We will have to wait and see what makes it into the enhancements and what don't. Meanwhile here is a video from Navid Abedini, Qualcomm from IEEE Sarnoff Symposium, 2019




Related Posts:

Tuesday, 12 February 2019

Prof. Andy Sutton: 5G Radio Access Network Architecture Evolution - Jan 2019


Prof. Andy Sutton delivered his annual IET talk last month which was held the 6th Annual 5G conference. You can watch the videos for that event here (not all have been uploaded at the time of writing this post). His talks have always been very popular on this blog with the last year talk being 2nd most popular while the one in 2017 was the most popular one. Thanks also to IET for hosting this annual event and IET Tv for making this videos available for free.

The slides and video is embedded below but for new starters, before jumping to this, you may want to check out about 5G Network Architecture options in our tutorial here.




As always, this is full of useful information with insight into how BT/EE is thinking about deploying 5G in UK.

Related Posts:

Wednesday, 5 September 2018

LiFi can be a valuable tool for densification

LiFi has been popping up in the news recently. I blogged about it (as LED-Fi) 10 years back. While the concept has remained the same, many of the limitations associated with the technology has been overcome. One of the companies driving LiFi is Scottish startup called pureLiFi.


I heard Professor Harald Haas at IEEE Glasgow Summit speak about how many of the limitations of LiFi have been overcome in the last few years (see videos below). This is a welcome news as there is a tremendous amount of Visible Light Spectrum that is available for exploitation.


While many discussions on LiFi revolve round its use as access technology, I think the real potential lies in its use as backhaul for densification.

For 5G, when we are looking at small cells, every few hundred meters, probably on streetlights and lamp posts, there is a requirement for alternative backhaul to fiber. Its difficult to run fiber to each and every lamp post. Traditionally, this was solved by microwave solutions but another option available in 5G is Integrated Access and Backhauling (IAB) or Self-backhauling.


A better alternative could be to use LiFi for this backhauling between lamp posts or streetlights. This can help avoid complications with IAB when multiple nodes are close by and also any complications with the technology until it matures. This approach is of course being trialed but as the picture above shows, rural backhaul is just one option.
LiFi is being studied as part of IEEE 802.11bb group as well as its potential is being considered for 5G.

Here is a vieo playlist explaining LiFi technology in detail.




Further reading:

Tuesday, 3 July 2018

Terahertz and Beyond 100 GHz progress

There seems to be a good amount of research going on in higher frequencies to see how a lot more spectrum with a lot more bandwidth can be used in future radio communications. NTT recently released information about "Ultra high-speed IC capable of wireless transmission of 100 gigabits per second in a 300 GHz band". Before we discuss anything, lets look at what Terahertz means from this article.

Terahertz wave: Just as we use the phrase ‘kilo’ to mean 103 , so we use the term ‘giga’ to mean 109 and the term ‘tera’ to mean 1012 . “Hertz (Hz)” is a unit of a physical quantity called frequency. It indicates how many times alternating electric signals and electromagnetic waves change polarity (plus and minus) per second. That is, one terahertz (1 THz = 1,000 GHz) is the frequency of the electromagnetic wave changing the polarity by 1 × 1012 times per second. In general, a terahertz wave often indicates an electromagnetic wave of 0.3 THz to 3 THz.

While there are quite a few different numbers, this is the one that is most commonly being used. The following is the details of research NTT did.

In this research, we realized 100 Gbps wireless transmission with one wave (one carrier), so in the future, we can extend to multiple carriers by making use of the wide frequency band of 300 GHz band, and use spatial multiplexing technology such as MIMO and OAM. It is expected to be an ultra high-speed IC technology that enables high-capacity wireless transmission of 400 gigabits per second. This is about 400 times the current LTE and Wi-Fi, and 40 times 5G, the next-generation mobile communication technology. It is also expected to be a technology that opens up utilization of the unused terahertz wave frequency band in the communications field and non-communication fields.

Complete article and paper available here.

Huawei has also been doing research in W (92 - 114.5 GHz) and D (130 - 174.5 GHz) bands.


A recent presentation by Debora Gentina, ETSI ISG mWT WI#8 Rapporteur at the UK Spectrum Policy Forum is embedded below.



This presentation can be downloaded from UK SPF site here. Another event on beyond 100GHz that took place last year has some interesting presentations too. Again, on UKSPF site here.


Ericsson has an interesting article in Technology Review, looking at beyond 100GHz from backhaul point of view. Its available here.

If 5G is going to start using the frequencies traditionally used by backhaul then backhaul will have to start looking at other options too.

Happy to listen to your thoughts and insights on this topic.

Sunday, 18 March 2018

Small Cells, Macrocells, Backhaul, Infrastructure and other connectivity solutions from #MWC18


Well, it was officially 3G4G's first Mobile World Congress so I took time to go through the different booths, demos, etc. and compile a small presentation

The presentation (embedded below and can be downloaded from Slideshare) covers the following companies:

Acceleran
Action Technologies
Airspan
Altiostar
Azcom
BaiCells
BravoCom
CBNL
CCS
Ceragon
Comba Telecom
Commscope
Fingu
Gemtek
IP.Access
JMA Wireless
Kleos
MitraStar
NuRAN
Parallel Wireless
Polaris Networks
Qualcomm
Qucell
Raycap
Ruckus
SOLiD
SpiderCloud
Vodafone
Zinwave



Do let me know if you found it useful


Related Posts:



Thursday, 25 January 2018

5G Network Architecture, Design and Optimisation - Jan 2018


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.



The video of this talk as follows:


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.

Related Links:

Saturday, 15 April 2017

Self-backhauling: Integrated access and backhaul links for 5G


One of the items that was proposed during the 3GPP RAN Plenary #75 held in Dubrovnik, Croatia, was Study on Integrated Access and Backhaul for NR (NR = New Radio). RP-17148 provides more details as follows:

One of the potential technologies targeted to enable future cellular network deployment scenarios and applications is the support for wireless backhaul and relay links enabling flexible and very dense deployment of NR cells without the need for densifying the transport network proportionately. 

Due to the expected larger bandwidth available for NR compared to LTE (e.g. mmWave spectrum) along with the native deployment of massive MIMO or multi-beam systems in NR creates an opportunity to develop and deploy integrated access and backhaul links. This may allow easier deployment of a dense network of self-backhauled NR cells in a more integrated manner by building upon many of the control and data channels/procedures defined for providing access to UEs. An example illustration of a network with such integrated access and backhaul links is shown in Figure 1, where relay nodes (rTRPs) can multiplex access and backhaul links in time, frequency, or space (e.g. beam-based operation).

The operation of the different links may be on the same or different frequencies (also termed ‘in-band’ and ‘out-band’ relays). While efficient support of out-band relays is important for some NR deployment scenarios, it is critically important to understand the requirements of in-band operation which imply tighter interworking with the access links operating on the same frequency to accommodate duplex constraints and avoid/mitigate interference. 

In addition, operating NR systems in mmWave spectrum presents some unique challenges including experiencing severe short-term blocking that cannot be readily mitigated by present RRC-based handover mechanisms due to the larger time-scales required for completion of the procedures compared to short-term blocking. Overcoming short-term blocking in mmWave systems may require fast L2-based switching between rTRPs, much like dynamic point selection, or modified L3-based solutions. The above described need to mitigate short-term blocking for NR operation in mmWave spectrum along with the desire for easier deployment of self-backhauled NR cells creates a need for the development of an integrated framework that allows fast switching of access and backhaul links. Over-the-air (OTA) coordination between rTRPs can also be considered to mitigate interference and support end-to-end route selection and optimization.

The benefits of integrated access and backhaul (IAB) are crucial during network rollout and the initial network growth phase. To leverage these benefits, IAB needs to be available when NR rollout occurs. Consequently, postponing IAB-related work to a later stage may have adverse impact on the timely deployment of NR access.


There is also an interesting presentation on this topic from Interdigital on the 5G Crosshaul group here. I found the following points worth noting:

  • This will create a new type of interference (access-backhaul interference) to mitigate and will require sophisticated (complex) scheduling of the channel resources (across two domains, access and backhaul).
  • One of the main drivers is Small cells densification calling for cost-effective and low latency backhauling
  • The goal would be to maximize efficiency through joint optimization/integration of access and backhaul resources
  • The existing approach of Fronthaul using CPRI will not scale for 5G, self-backhaul may be an alternative in the shape of wireless fronthaul

Let me know what you think.

Related Links:



Sunday, 18 September 2016

5G Fronthaul: Crosshaul & XHaul

I have written about Fronthaul as part of C-RAN in this blog as well as in the Small Cells blog. I am also critical of the C-RAN concept now that the Baseband Units (BBU) have become small enough to go on the cell cite. I have expressed this view openly as can be seen in my tweet below.



While I am critical of the C-RAN approach, there are many vendors and engineers & architects within these vendors who are for or against this technology. I am going to leave the benefits and drawbacks of C-RAN in light of new developments (think Moore's law) for some other day.

The above picture from my earlier post explains the concept of Fronthaul and Backhaul for anyone who may not be aware. As data speeds keep on increasing with 4G, 4.5G, 4.9G, 5G, etc. it makes much more sense to use Fiber for Fronthaul. Dark fiber would be a far better choice than a lit one.

One thing that concerned me was what happens in case of MIMO or massive MIMO in 5G. Would we need multiple Fronthaul/Fibre or just a single one would do. After having some discussions with industry colleagues, looks like a single fiber is enough.

This picture above from an NTT presentation illustrates how WDM (Wavelength Division Multiplexing) can be used to send different light wavelengths over a single fiber thereby avoiding the need to have multiple of these fibers in the fronthaul.


There are 2 different projects ongoing to define 5G Fronthaul & Backhaul.

The first of these is 5G Crosshaul. Their website says:

The 5G-Crosshaul project aims at developing a 5G integrated backhaul and fronthaul transport network enabling a flexible and software-defined reconfiguration of all networking elements in a multi-tenant and service-oriented unified management environment. The 5G-Crosshaul transport network envisioned will consist of high-capacity switches and heterogeneous transmission links (e.g., fibre or wireless optics, high-capacity copper, mmWave) interconnecting Remote Radio Heads, 5GPoAs (e.g., macro and small cells), cloud-processing units (mini data centres), and points-of-presence of the core networks of one or multiple service providers. This transport network will flexibly interconnect distributed 5G radio access and core network functions, hosted on in-network cloud nodes, through the implementation of: (i) a control infrastructure using a unified, abstract network model for control plane integration (Crosshaul Control Infrastructure, XCI); (ii) a unified data plane encompassing innovative high-capacity transmission technologies and novel deterministic-latency switch architectures (Crosshaul Packet Forwarding Element, XFE).

The second is 5G XHaul. Their website says:

5G-XHaul proposes a converged optical and wireless network solution able to flexibly connect Small Cells to the core network. Exploiting user mobility, our solution allows the dynamic allocation of network resources to predicted and actual hotspots. To support these novel concepts, we will develop:
  • Dynamically programmable, high capacity, low latency, point-to-multipoint mm-Wave transceivers, cooperating with Sub-6 GHz systems;
  • A Time Shared Optical Network offering elastic and fine granular bandwidth allocation, cooperating with advanced passive optical networks;
  • A software-defined cognitive control plane, able to forecast traffic demand in time and space, and the ability to reconfigure network components.
The well balanced 5G-XHaul consortium of industrial and research partners with unique expertise and skills across the constituent domains of communication systems and networks will create impact through:
  • Developing novel converged optical/wireless architectures and network management algorithms for mobile scenarios;
  • Introduce advanced mm-Wave and optical transceivers and control functions;
  • Support the development of international standards through technical and technoeconomic contributions.
The differences are summarised in the document below:



It remains to be seen if C-RAN will play a big role in 5G. If yes how much of Crosshaul and XHaul will help.

Further reading:



Saturday, 28 June 2014

EE: The Implications of RAN Architecture Evolution for Transport Networks


Here is a presentation by Andy Sutton, EE from the recent LTE World Summit 2014. Unfortunately the event was too big to be present in all presentations but in his own words, "As always the bullet points don’t tell the full story as there’s considerable narrative that goes with this, however it does stress some major themes."

Slides embedded below, can be downloaded from Slideshare:


Sunday, 23 March 2014

Securing the backhaul with the help of LTE Security Gateway


An excellent presentation from the LTE World Summit last year, that is embedded below. The slide(s) that caught my attention was the overhead involved when using the different protocols. As can be seen in the picture above, the Ethernet MTU is 1500 bytes but after removing all the overheads, 1320 bytes are left for data. In case you were wondering, MTU stands for 'maximum transmission unit' and is the largest size packet or frame, specified in octets (8-bit bytes), that can be sent in a packet or frame based network such as the Internet.

Anyway, the presentation is embedded below:


Monday, 3 February 2014

5G and the ‘Millimeter-Wave' Radios


There were quite a few interesting talks in the Cambridge Wireless Radio Technology SIG event last week. The ones that caught my attention and I want to highlight here are as follows.

The mobile operator EE and 5GIC centre explained the challenges faced during the Practical deployments. Of particular interest was the considerations during deployments. The outdoor environments can change in no time with things like foliage, signage or even during certain festivals. This can impact the radio path and may knock out certain small cells or backhaul. The presentation is available to view and download here.


Another interesting presentation was from Bluwireless on the 60GHz for backhaul. The slide that was really shocking was the impact of regulation in the US and the EU. This regulation difference means that a backhaul link could be expensive and impractical in certain scenarios in the EU while similar deployments in the US would be considerably cheaper. This presentation is available here.


Finally, the presentation from Samsung highlighted their vision and showed the test results of their mmWave prototype. The presentation is embedded below and is available here.



Finally, our 5G presentation summarising our opinion and what 5G may contain is available here. Dont forget to see the interesting discussion in the comments area.

Thursday, 3 October 2013

Case study of SKT deployment using the C-RAN architecture


Recently I came across this whitepaper by iGR, where they have done a case study on the SKT deployment using C-RAN. The main point can be summarised from the whitepaper as follows:

This approach created several advantages for SK Telecom – or for any operator that might implement a similar solution – including the:

  • Maximum re-use of existing fiber infrastructure to reduce the need for new fiber runs which ultimately reduced the time to market and capital costs.
  • Ability to quickly add more ONTs to the fiber rings so as to support additional RAN capacity when needed.
  • Support of multiple small cells on a single fiber strand. This is critical to reducing costs and having the flexibility to scale.
  • Reduction of operating expenses.
  • Increased reliability due to the use of fiber rings with redundancy.
  • Support for both licensed and unlicensed RAN solutions, including WiFi. Thus, the fronthaul architecture could support LTE and WiFi RANs on the same system.
As a result of its implementation, SK Telecom rolled out a new LTE network in 12 months rather than 24 and reduced operating expenses in the first year by approximately five percent. By 2014, SK Telecom expects an additional 50 percent OpEx savings due to the new architecture.

Anyway, the paper is embedded below for your perusal and is available to download from the iGR website here.



Monday, 12 August 2013

C-RAN Architecture and Challenges


I have blogged about Cloud RAN or C-RAN in the Metrocells blog here and am looking forward to more discussions on this topic in the SON conference later this year.


I came across this interesting presentation from Orange in the LTE World Summit this year where the authors have detailed the C-RAN architecture and also discussing the fronthaul challenges faced by C-RAN. The presentation is embedded as follows. Please feel free to add your comments with your opinions.




Sunday, 30 June 2013

Multi-RAT mobile backhaul for Het-Nets

Recently got another opportunity to hear from Andy Sutton, Principal Network Architect, Network Strategy, EE. His earlier presentation from our Cambridge Wireless event is here. There were many interesting bits in this presentation and some of the ones I found interesting is as follows:

Interesting to see in the above that the LTE traffic in the backhaul is separated by the QCI (QoS Class Identifiers - see here) as opposed to the 2G/3G traffic.




This is EE's implementation. As you may notice 2G and 4G use SRAN (Single RAN) while 3G is separate. As I mentioned a few times, I think 3G networks will probably be switched off before the 2G networks, mainly because there are a lot more 2G M2M devices that requires little data to be sent and not consume lots of energy (which is an issue in 3G), so this architecture may be suited well.


Finally, a practical network implementation which looks different from the text book picture and the often touted 'flat' architecture. Andy did mention that they see a ping latency of 30-50ms in the LTE network as opposed to around 100ms in the UMTS networks.


Mark Gilmour was able to prove this point practically.

Here is the complete presentation:



Wednesday, 10 October 2012

Small Cell Backhaul Solution Types

This is from a presentation by Julius Robson of CBNL, representing NGMN in the Cambridge Wireless Small Cells SIG event.
Interesting to see all possible options for Backhaul for small cells.

The presentation is available to view and download from here.

Related blog posts: