5G RAN Functional Splits

I have been meaning to write a post on RAN functional splits and even make a video. Recently I came across multiple of these things so I am taking a shortcut by posting them here. 

The first is this basic introductory video from Parallel Wireless where they explain why you need RAN splits providing examples of various functional splits for 4G and 5G mobile networks. It is embedded below:

The next one is slightly detailed video from the book "5G Radio Access Network Architecture: The Dark Side of 5G" by Sasha Sirotkin (Editor). I wrote a review of the book here and Sasha kindly made a video for our channel which is embedded below:

Finally, RCR Wireless published an article looking at the 5G functional splits in detail, by Ankur Sharma, Associate Vice President, Product Management and Strategy, Radisys. The article 'Exploring functional splits in 5G RAN: Tradeoffs and use cases' is available here.

Feel free to suggest other videos, articles, etc. in comments.

Related Posts:

• 3G4G: Book review - 5G Radio Access Network Architecture: The Dark Side of 5G by Sasha Sirotkin (Editor)
• The 3G4G Blog: The Status of 5G Standalone (5G SA) Networks - March 2021
• The 3G4G Blog: Initiative to Remove Non-inclusive terms from 3GPP Specifications
• The 3G4G Blog: Everything you need to know about 5G Security
• The 3G4G Blog: Open RAN Explanation, Videos, White papers and Other Resources
• The 3G4G Blog: Free 6G Training 

Evolution of 3G Networks: The Concept, Architecture and Realisation of Mobile Networks beyond UMTS

This book has a title that can be a bit misleading but the main focus is on LTE network. One of the main problems that I generally notice is the lack of understanding of the bigger picture from the network point of view. This book can help fill that gap. The book starts with Mobile Network Evolution in General and moves to explain the evolved 3GPP network.

The different layers and interfaces have been explained quite well and the concepts have been well illustrated with the diagrams. A lot of books have diagrams that are verbatim copy of the standards of illustrated in a complicated way, these have been avoided in this book. To illustrate my point lets look at this image below that shows example arrangement of bearers with multiple PDN connectivity.

Later on the signalling for different scenarios have been explained in a rather nice way. For example of we look at PDN connectivity again, its rather simply explained.

There are many examples of signalling and once they are complete, there is a chapter looking at different protocols like GTP, PMIP, DIAMATER, SCTP, etc.

The book is a bit pricey though but worth the investment if your focus is on the signalling side of things and if you are required to understand the concepts quite well. You can also have a look at the book n google books as embedded below:

Book Review - Femtocells: Opportunities and Challenges for Business and Technology

Femtocells: Opportunities and Challenges for Business and Technology
by Simon Saunders, Stuart Carlaw, Andrea Giustina, Ravi Rai Bhat, V. Srinivasa Rao

This is not a very thick book with just 252 pages. Someone may say that there is not much to write about Femtocells. I say that you can fill couple of thousand pages not with much difficulty on Femtocells but it is important to seperate the useful things that everyone will be interested in and just keep that in the book. When I told a colleague that a new book on Femtocells is out, the first question he asked me jokingly is does it cover 'Zero Touch'. The answer is, yes it does ;)

It starts with the very basic what Femtocell is and what its not, goes on to talk about the types, the user benefits, Attributes, applications, challenges, etc.

It then goes on to examine the background for small cells, placing femtocells in the context of the history of other solutions for in-building service and explains the market and technological factors which have made femtocells a compelling proposition. It also addresses market issues, covering the benefits and motivations of femtocells for operators, the key market challenges, business case analysis and forecasts for the take-up of femtocells.

Chapter 4 covers radio issues for femtocells, including the requirements and methods for interference management between femtocells, femtocell RF specifications and health issues. There is a very good table that lists out the potential problems of using Femtocells.

The next chapter covers the network architecture of femtocells, particularly the interfaces and protocols for integrating femtocells with the operator network across the Internet and the way in which the various options differ between standards families. This chapter also introduces the 3GPP based Iuh interface for Home NodeB's. There are other interesting Femto architectures like the CDMA based, WiMAX based, GSM based and LTE based covered in this as well.

Then there is a chapter on the Management of Femto's that describes the requirements and approaches for provisioning and managing millions of femtocells in an efficient and scalable fashion. It explains about the TR-069 data structure and management protocol.

Chapter 7 is dedicated to the very important topic of Security. It explains the security aspects of femtocells from a customer and operator perspective, including analysis of the potential threats and solutions.

Chapter 8 covers the standards for femtocells across the main mobile standards families, namely 3GPP, 3GPP2 and WiMAX Forum. It also introduces the industry bodies who are playing important roles in the introduction and proliferation of femtocells. There is a list of all the 3GPP standards for the Home NodeB and Home eNodeB.

Finally there are chapters on Regulation (including lawful interception, etc.), Implementation Considerations (showing refrerence designs, etc.), Business and Service Options (with examples of scenarios and service options) followed by a Summary.

You can learn more about this book from its official website at http://www.femtocellbook.com/

There are lots of things I may not agree on and there are things i would like to argue about but overall It looks like an interesting book especially for people who either work in or follow femtocells area. With the femtocell information scarce at the moment, this book is like information goldmine for readers. I would be interested in hearing from any readers about their opinion of this book.

Dictionary of LTE Acronyms

A comprehensive dictionary of LTE acronyms has just been released, providing a useful aid to understanding the LTE specification documents.

A companion to the highly-acclaimed book on LTE, “LTE – The UMTS Long Term Evolution: From Theory to Practice”, the new dictionary provides not just the expansion of each acronym, but significantly also a concise explanation. The dictionary will enable engineers and researchers to find their way through the often bewildering array of acronyms and to understand the LTE specifications with renewed ease.

Written by the editors of the companion book, Stefania Sesia, Issam Toufik and Matthew Baker, from the major telecommunications companies ST-Ericsson and Alcatel-Lucent, the dictionary is available to download free-of-charge from the website of the publisher, John Wiley & Sons:

Download the dictionary from here.

Testing UMTS protocols

Testing UMTS by Dan Fox, Anritsu

Its nearly three years since I wrote an FAQ on UMTS Testing. So when I got my hands on this book the other day, I so wanted to read it. It would be a while before I manage to go through the book in detail but my initial impression is that this book looks quite good.

Since the book deals with Protocol Testing, the testing has been grouped into three categories:

1. Integration Testing
2. Conformance Testing
3. Interoperability Testing

There is a chapter explaining each of these. The Conformance testing is of interest to me as I have been involved directly and indirectly with this for quite some years now. The book explains the process, standards required and submission of tests to GCF/PTCRB.

For those whom testing does not hold much charm, they can gain greater understanding of the concepts by reading Part II of the book. One thing I really liked in this book is that the diagrams explain the concepts very well. Rather than copying them straight from the 3GPP specifications, they have been improved and re-done by the author. Basic things like 'Dynamic TFCI selection' and 'Layer 2 transport channel processing flow for the 12.2 kbps RMC' are explained clearly using the diagrams.

There is just the right amount of detail in the chapters for Physical Layer, Layer 2 (MAC, RLC, PDCP) and Layer 3 (RRC, NAS). Further chapters show message flow sequence charts explaining things like 'setting up of speech call' and 'location updating procedure'. I have some basic sequence diagrams for message flow in the Tutorial section but the ones in the book are comparatively more detailed.

The book mainly covers UMTS, with an introduction to HSPA. It would be worthwhile to have the next edition covering LTE in detail. The main reason being that there are lots of changes in the case of LTE. The Air Interface has changed, the channels are different. The NAS messages and entities are different. UMTS (and HSPA) use TTCN-2 for testing but LTE uses TTCN-3. UMTS does not use MIMO (MIMO available for HSPA from Release 7 onwards) but LTE would generally always use MIMO.

Overall, this seems to be a useful book and I am looking forward to reading it in detail.

GSM: Architecture, Protocols and Services

There is a new book on GSM in the market. Now it makes me wonder that since we are all focussing on 3.6G, 3.75G, 3.9G, 4G, etc., etc. what would be the point of a GSM book?

The following is from the preface of the book:

The GSM family (GSM, GPRS, EDGE) has become one of the most successful technical innovations in history. As of June 2008, more than 2.9 billion subscribers were using GSM, corresponding to a market share of more than 81%, and its story continues, even now, despite the introduction and development of next-generation systems such as IMT-2000 or UMTS (3G) and even systems beyond 3G, dubbed IMT-Advanced.

At the same time, wireless local area networks have substantially expanded the wireless market, sometimes drawing market share from GPRS and 3G (e.g. in public WiFi hotspots), sometimes coexisting (e.g. in UMTS home routers used as a replacement for fixed wire connections). However, these are used typically for low mobility applications. Mobile communication with all of its features and stability has become increasingly important: cellular and GSM technology, plus, of course, lately 3G, GSMs sister technology, so-to-say.

Another impressive trend has emerged since our last edition: the permanent evolution in the handheld market, producing fancy mobile phones with cameras, large memory, MP3 players, Email clients and even satellite navigation. These features enable numerous nonvoice or multimedia applications, from which, of course, only a subset is or will be successful on the market.

In this third edition, we concentrate again on the architecture, protocols and operation of the GSM network and outline and explain the innovations introduced in recent years. The main novelties in this book are the presentation of capacity enhancement methods such as sectorization, the application of adaptive antennas for Spatial Filtering for Interference Reduction (SFIR) and Space Division Multiple Access (SDMA), a detailed introduction to HSCSD and EDGE for higher data rates, and an update of the available GSM services, specifically introducing the Multimedia Messaging Service (MMS).

I think that GSM is going to be the fallback option for most of the new technologies due to its worldwide deployment so now is the time for us to brush up our GSM concepts

Parlay, OSA, etc

Parlay (as opposed to Parley in 'Pirates of the Carribean') integrates telecom network capabilities with IT applications via a secure, measured, and billable interface. Parlay's open application programming interfaces (APIs) release developers from having to write code for specific networks and environments, reducing risks and costs, and allowing for innovative new services to be delivered via the telco network-operator channel. Enabled by Parlay's network-independent APIs, applications are generating new revenue streams for network operators, application service providers (ASPs), and independent software vendors (ISVs).

Today, where each service interacts individually with different network elements, ParlayAPIs can be useful.

These APIs will allow you to access same services regardless of whether you are using a Mobile phone or a fixed line phone or a PC thereby creating a Virtual Home Environment (VHE).

Many different organisations are part of the Parley group including 3GPP, ETSI, OMA, ITU to name a few.

Finally if you find this interesting then you may want to read "Parlay/OSA: From Standards to Reality".

More:

• The Parlay group
• ETSI 2006 workshop on Parlay OSA

If you have any further pointers explaining relationships between Parlay, OSA, SOA, JAIN, CORBA, TINA-C, IMS, NGN, VHE, etc. Please post a comment and let us know.