Qualcomm Explains 5G Millimeter Wave (mmWave) Future & Integrated Access and Backhaul (IAB)

We have covered various topics in our blog posts on millimeter wave spectrum and even going beyond 52.6 GHz in FR2. A Qualcomm webinar from back in January expands on many of the topics that I looked superficially in various posts (links at the bottom).

The following is edited from the Qualcomm blog post:

5G NR in unlicensed spectrum (NR-U) was standardized in Release 16 and it is a key enabler for the 5G expansion to new use cases and verticals, providing expanded spectrum access to mobile operators, service providers, and industry players. At the same time, we are starting to push the mmWave boundary to even higher bands toward the sub-Terahertz (i.e., >100 GHz) range. Expected in Release 17, 5G NR will support spectrum bands up to 71 GHz, leveraging the 5G NR Release 15 scalable numerology and flexible framework. This opens up 5G to operate in the globally unlicensed 60 GHz band, which can fuel a broad range of new applications and deployments.

One daunting challenge that mobile operators will face when expanding 5G mmWave network coverage is the cost of deploying additional base stations for mmWave, which usually requires new fiber optics backhaul installations. Release 16-defined IAB allows a base station to not just provide wireless access for its user devices (e.g., smartphones) but also the ability to backhaul wirelessly via neighboring base stations using the same mmWave spectrum. IAB opens the door to more flexible densification strategies, allowing mobile operators to quickly add new base stations to their networks before having to install new fiber to increase backhaul capacity. 

Release 16 established foundational IAB capabilities, such as dynamic topology adaptation for load balancing and blockage mitigation, and Release 17+ will further enhance IAB by bringing new features like full-duplex operation, topology redundancy, and ML-based network management.

Beyond IAB, there is a rich roadmap of other new features that can further improve 5G mmWave system performance and efficiency. The webinar embedded below is presented by Ozge Koymen, Senior Director, Technology, Qualcomm Technologies, Inc. It covers the following topics:

• Qualcomm's vision for 5G mmWave and the new opportunities it poises to bring for the broader ecosystem
• mmWave capabilities and enhancements coming in Release -16 and beyond
• Qualcomm’s role in mobilizing and democratizing 5G mmWave to usher in new experiences
• Latest update on the global commercial rollout of 5G mmWave networks and devices

Slides of the presentation are available here.

Related Posts:

• Free 6G Training: Spectrum for 5G, Beyond 5G and 6G research
• The 3G4G Blog: A mmWave Special Cell in Open RAN Environment
• The 3G4G Blog: Spectrum for 5G NR beyond 52.6 GHz
• The 3G4G Blog: 5G Integrated Access and Backhaul (IAB) Enhancements in Rel-17
• The 3G4G Blog: Carrier Aggregation (CA) and Dual Connectivity (DC)
• The 3G4G Blog: The Politics of Standalone vs Non-Standalone 5G & 4G Speeds 

Network Slicing Tutorials and Other Resources

I have received quite a few requests to do a 5G Network Slicing tutorial but have still not got around to doing it. Luckily there are so many public resources available that I can get away with not doing one on this topic. 

This Award Solutions webinar by Paul Shepherd (embedded below) provides good insights into network slicing, what it is, how it efficiently enables different services in 5G networks, and the architectural changes in 5G required to support it.

Then there is also this myth about 3 slices in the network. The GSMA slice template is a good starting point for an operator looking to do network slicing in their 5G networks. The latest version is 3.0, available here.

As this picture (courtesy of Phil Kendall) shows, it's not a straightforward task.  

That is 37 attributes each of which can take multiple values. The permutations are massive.

— Dr. Dan Warren (@TMGB) October 18, 2019

Alistair URIE from Nokia Bell Labs points out some common misconceptions people have with Network Slicing:

1. Multiple slices may share the same cell and the same RU in each slice
2. Single UE may have up to 8 active slices but must have a single CU-CP instance to terminate the common RRC 
3. Slicing supports more than 3 slices 

Back in March, China Mobile, Huawei, Tencent, China Electric Power Research Institute, and Digital Domain have jointly released the Categories and Service Levels of Network Slice White Paper to introduce the industry’s first classification of network slice levels. The new white paper dives into the definitions, solutions, typical scenarios, and evolution that make up the five levels of network slices. It serves as an excellent reference to provide guidance in promoting and commercializing network slicing, and lays a theoretical foundation for the industry-wide application of network slicing.

The whitepaper describes the different phases as:

Phase 1 (ready): As mentioned above, the 5G transport network and 5G core network support different software-based and hardware-based isolation solutions. On the 5G NR side, 5QIs (QoS scheduling mechanism) are mainly used to achieve software-based isolation in WAN scenarios. Alternatively, campus-specific 5G NR (including micro base stations and indoor distributed base stations) is used to implement hardware-based isolation in LAN scenarios. In terms of service experience assurance, 5QIs are used to implement differentiated SLA assurance between slices. In terms of slice OAM capabilities, E2E KPIs can be managed in a visualized manner. This means that from 2020 on, Huawei is ready to deliver commercial use of E2E slicing for common customers and VIP customers of the public network and common customer of general industries (such as UHD live broadcast and AR advertisement).

Phase 2 (to be ready in 2021): In terms of isolation, the 5G NR side supports the wireless RB resource reservation technology (including the static reservation and dynamic reservation modes) to implement E2E network resource isolation and slicing in WAN scenarios. In terms of service experience assurance, features such as 5G LAN and 5G TSN are enhanced to implement differentiated and deterministic SLA assurance between different slices. In terms of slice OAM, on the basis of tenant-level KPI visualization, the limited self-service of the industry for rented slices can be further supported. In this phase, operators can serve VIP customers in common industries (such as AR/VR cloud games and drone inspection), dedicated industry customers (such as electric power management information region, medical hospital campus, and industrial campus), and dedicated industry customers (such as electric power production control region and public security).

Phase 3 (to be ready after 2022): In this phase, 5G network slicing supports real dynamic closed-loop SLAs based on AI and negative feedback mechanism, implementing network self-optimization and better serving industries (such as 5G V2X) with high requirements on mobility, roaming, and service continuity. In addition, industry-oriented comprehensive service capabilities will be further enhanced and evolved.

A more technical presentation from Nokia is available here. The video below shows how innovations in IP routing and SDN work together to implement network slicing in the transport domain.

If you know some other good resources and tutorials worth sharing, add them in the comments below.

Related Posts:

• The 3G4G Blog: 5G Slicing Templates
• The 3G4G Blog: End-to-end Network Slicing in 5G
• The 3G4G Blog: AI your Slice to 5G Perfection 

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

Prof. Andy Sutton: Backhauling the 5G Experience from 3G4G

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:

• Prof. Andy Sutton: 5G Radio Access Network Architecture Evolution - Jan 2019
• Prof. Andy Sutton: 5G Network Architecture, Design and Optimisation - Jan 2018
• Prof. Andy Sutton: 5G Network Architecture and Design Update - Jan 2017
• Prof. Andy Sutton #CWHeritage Talk: The History of Synchronization in Digital Cellular Networks
• Connectivity Technology Blog: An Introduction to Different Types of Backhaul
• 5G Evolution with Matthew Baker, Nokia
• Exploring Network Convergence of Mobile, Broadband and Wi-Fi
• 5G and Fixed-Mobile Convergence (FMC)

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:

• Connectivity Technology Blog: Integrated Access and Backhauling (IAB) - Today and Tomorrow
• 5G Evolution with Matthew Baker, Nokia
• Summary of #CWTEC 2019 Conference: 5G, Satellites & Magic MIMO
• 5G and Fixed-Mobile Convergence (FMC)
• R&S Webinar on LTE-A Pro and evolution to 5G
• Introduction to NR-Light a.k.a. NR-Lite
• An Introduction to Non-Terrestrial Networks (NTN)

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.

Prof. Andy Sutton: 5G RAN Architecture Evolution - Jan 2019 from 3G4G

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

Related Posts:

• Dr. Yue Wang: AI in 5G – the why and how - The 3G4G Blog
• CWHeritage Talk by Prof. Andy Sutton: The history of synchronisation in digital cellular networks - The 3G4G Blog
• Prof. Andy Sutton: 5G Network Architecture, Design and Optimisation - Jan 2018 - The 3G4G Blog
• 5G Network Architecture Options (Updated) - The 3G4G Blog
• 5G (IMT-2020) Wireless Resources - 3G4G Homepage

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:

• O2 uses light to transmit data in latest network trial
• IEEE Task Force Works on Standard for Light Communications
• Learn How Li-Fi Works from Its Inventor, Harald Haas
• Light Communications for Wireless Local Area Networking
• LiFi can bring enhanced connectivity to your workspace, while also enhancing data security

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.

NTT Docomo has been doing 5G Field Testing of Ultra-high-speed, Long-distance Transmission Using mmWave in 28, 39 GHz in collaboration with @Huawei . Achieved high speed communication over distances exceeding 1 km with mmWave - https://t.co/a03SdqVhI7 pic.twitter.com/rlsqRAJ5YC

— 3G4G (@3g4gUK) July 2, 2018

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.

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

Our first official #MWC18 thanks to @Parallel_tw. Do wave to @zahidtg when you see him around pic.twitter.com/ETR9oU21z9

— 3G4G (@3g4gUK) February 26, 2018

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

Small Cells, Macrocells, Backhaul, Infrastructure and other connectivity solutions from #MWC18 from 3G4G

Do let me know if you found it useful


Related Posts:

• Quick summary of Mobile World Congress 2018 (#MWC18)
• LoRa is quietly marching on...

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.

5G Network Architecture, Design and Optimisation from 3G4G

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:

• [Video] The UK’s first end-to-end 5G network test - EE
• [Video] 5G Network Architecture Options - 3G4G
• [Video] Beginners: 5G Terminology - 3G4G
• 3GPP-VRIF workshop on Virtual Reality Ecosystem & Standards in 5G
• Ultra Reliable Low Latency Communications (URLLC) 2017 Conference summary

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:

• Backhauling problems driving up deployment costs?

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.

Someone finally said it - "Fronthaul is a manmade problem." #CRAN #5G https://t.co/B1uuJqLiQy

— Zahid Ghadialy (@zahidtg) September 1, 2016

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:

5G Crosshaul vs 5G-XHaul from 3G4G

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:

• Fronthaul and backhaul: Look out, a fusion is coming! - Alan Carlton, Interdigital
• RAN Evolution Project: Backhaul and Fronthaul Evolution - NGMN
• Examining the fronthaul opportunities for future radio access - Shigeru Kuwano, NTT Access Network Service Systems
• 5 Things You Need to Know About vRAN: “vRAN architecture: centralize or distribute” - Amir Atai, Parallel Wireless
• 5G-XHaul project looks at WDM-PON for mobile fronthaul, backhaul - Lightwave
• Why WDM is essential in C-RAN fronthaul networks? - Ultra high CPRI link capacity - Steve Shin and Dr. Harrison J. Son, Netmanias
• Fronthaul Evolution Toward 5G: Standards and Proof of Concepts

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:

The Implications of RAN Architecture Evolution for Transport Networks from Zahid Ghadialy

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:

Securing the backhaul from 3G4G Blogs

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.

Vision and Key Features for 5th Generation (5G) Cellular - Samsung from Zahid Ghadialy

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.

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.

Fronthaul: The New Paradigm for Enabling the Het-Net from Zahid Ghadialy

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.

C-RAN architecture and fronthaul challenges from Zahid Ghadialy

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:

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