Refresher: LTE RLC Layer Protocol

LTE RLC Layer Protocol

View more presentations from All About 4G.

6LoWPAN: Low power Wireless Personal Area Networks

From Wikipedia: 6lowpan is an acronym of IPv6 over Low power Wireless Personal Area Networks, or (as the "personal" qualification is no longer relevant), IPv6 over LoW Power wireless Area Networks. 6lowpan is the name of a working group in the internet area of the IETF. The 6lowpan group has defined encapsulation and header compression mechanisms that allow IPv6 packets to be sent to and received from over IEEE 802.15.4 based networks. IPv4 and IPv6 are the work horses for data delivery for local-area networks, metropolitan area networks, and wide-area networks such as the Internet.

There is a book from Wiley entitled "6LoWPAN: The Wireless Embedded Internet", which has a good definition and explanation of 6LoWPAN that I am using below. Wiley has excerpt from the book that details the complete introductory chapter.

As the Internet of routers, servers and personal computers has been maturing, another Internet revolution has been going on – The Internet of Things (see pic below). The vision behind the Internet of Things is that embedded devices, also called smart objects, are universally becoming IP enabled, and an integral part of the Internet. Examples of embedded devices and systems using IP today range from mobile phones, personal health devices and home automation, to industrial automation, smart metering and environmental monitoring systems. The scale of the Internet of Things is already estimated to be immense, with the potential of trillions of devices becoming IP-enabled. The impact of the Internet of Things will be significant, with the promise of better environmental monitoring, energy savings, smart grids, more efficient factories, better logistics, better healthcare and smart homes.

The Internet of Things can be understood as a layer of digital information that covers the physical world. Objects and places become part of the Internet of Things in two ways: First, data and information can be associated with a particular location, using geo-coordinates or a street address. Second with sensors and RFID tags or transmitters installed in these objects allowing then to be accessed via Internet protocols.

Remember, Ericsson has already predicted 50 Billion connected devices by 2050. See here.

The Institute of Electrical and Electronics Engineers (IEEE) released the 802.15.4 lowpower wireless personal area network (WPAN) standard in 2003, which was a major milestone, providing the first global low-power radio standard. Soon after, the ZigBee Alliance developed a solution for ad hoc control networks over IEEE 802.15.4, and has produced a lot of publicity about the applications of wireless embedded technology. ZigBee and proprietary networking solutions that are vertically bound to a link-layer and application profiles only solve a small portion of the applications for wireless embedded networking. They also have problems with scalability, evolvability and Internet integration.

The IEEE 802.15.4 standard released in 2003 was the biggest factor leading to 6LoWPAN standardization. For the first time a global, widely supported standard for lowpower wireless embedded communications was available [IEEE802.15.4]. The popularity of this new standard gave the Internet community the needed encouragement to standardize an IP adaptation for such wireless embedded links.

The ideal use of 6LoWPAN is in applications where:

• embedded devices need to communicate with Internet-based services,

• low-power heterogeneous networks need to be tied together,

• the network needs to be open, reusable and evolvable for new uses and services, and

• scalability is needed across large network infrastructures with mobility.

Connecting the Internet to the physical world enables a wide range of interesting applications where 6LoWPAN technology may be applicable, for example:

• home and building automation

• healthcare automation and logistics

• personal health and fitness

• improved energy efficiency

• industrial automation

• smart metering and smart grid infrastructures

• real-time environmental monitoring and forecasting

• better security systems and less harmful defense systems

• more flexible RFID infrastructures and uses

• asset management and logistics

• vehicular automation

One interesting example application of 6LoWPAN is in facility management, which is the management of large facilities using a combination of building automation, asset management and other embedded systems. This quickly growing field can benefit from 6LoWPAN, is feasible with today’s technology, and has real business demand.

You can read more from the book on Wiley's website here.

More information on purchasing and reviews on Amazon's website below:

The silent heroes of the wireless world

Often you will hear about some famous people from certain organisations who speak at conferences and meetings but there are often in the background many people who labour to ensure that reports, documents, presentations and technology are completed without problems.

Last Friday, I met up with some old colleagues who are these silent movers and shakers in our mobile industry. Often behind multiple monitors and pile of documents, these people work on the cutting edge future technologies. It was nice to know that they do read and refer to my blog from time to time and find it useful.

I should also like to mention the people who often mail me to thank me for the blog and the 3g4g website. I do quite often bump into people who know me for my work but dont know me personally. Sometimes they do get a bit surprised because my HQ (humour quotient) is very high. I have a jokelist active since 1999 and even though I dont get enough time to post jokes I do make it a point to keep it alive.

I am fortunate enough to learn a lot from such people, as knowledge is limitless and there is always something everyone can contribute as they may know it much better than others.

So please feel free to say hello to me when you come across me in any conference, presentation, party or even interviews. Its always good to know people.

Minimization of Drive Tests (MDT) in 3GPP Release-10

Another one that came from the SON conference.

At present, the network optimisation after it is operational is generally done by drive testing. In this an equipment (test mobile) that collects measurements and location information collects all the required information while the equipment is being driven in a car on the roads and this information is used offline to analyse the coverage in different locations and based on that the parameters, power, antenna locations, antenna tilts, etc. are optimised. After the changes to any of the optimisation paramaters, drive test has to be undertaken again to make sure that the impact of these changes are positive.

One more thing that has to be taken account of is that the drive tests have to be carried out at di9ffert times to be able to predeict the behaviour at different loads.

Using drive tests for network optimization purposes is costly and causes also additional CO2 emissions, so it is desirable to develop automated solutions, including involving UEs in the field, in 3GPP to reduce the operator costs for network deployment and operation. The studies done as part of the study item phase [1] have shown that it is beneficial to collect UE measurements to enable a more efficient network optimisation and it is feasible to use control plane solutions to acquire the information from devices. This information, together with information available in the radio access network can be used for Coverage Optimization purposes.

It should be remembered that drive tests form a big part of the Network opex and Deutsche Telekom for example expects a 40% cost saving with SON (and MDT is a part of that)

Goal of MDT in 3GPP Rel.10

– Automatic UE measurements collection and data logging used to replace the manual drive testing that the operators have to perform in their networks

– Evaluation of network performance per physical location

– For both HSPA & LTE

There are two different types of MDT:

Immediate MDT: MDT functionality involving measurement performance by UE in CONNECTED state and reporting of the measurements to eNB/RNC available at the time of reporting condition.

Logged MDT: MDT functionality involving measurement performance by UE in IDLE state at points in time when configured conditions are satisfied, its storage in measurement log for reporting to eNB/RNC at a later point in time.

The solutions for MDT shall be able to work independently from SON support in the network. Relation between measurements/solution for MDT and UE side SON functions shall be established in a way that re-use of functions is achieved where possible.

• Use cases

– 3GPP R10: Coverage optimization : Prio1

– For 3GPP > R10 :Capacity optimization, Mobility optimization, Parameterization of common channels, QoS verification, no specific measurements

- In Release-11 MDT Enhancements and evaluation of other MDT use cases, such as ”Parameterization of common control channels” and Positioning enhancements will be explored.

• MDT and SON

– MDT is about UE measurement collection for off-line processing No automatic mechanism is defined MDT

– SON is aiming at instantaneous/automated reaction on short to middle term network issues

It should be noted that MDT is a wide area and some of the boundaries between MDT and SON are a bit fuzzy. One of the other ways for SON is to enable detected cell measurements in the handset. This will give the indication about the cells that are not in the monitored set but the UE is able to see.

The RRC (control plane) measurements for LTE are not advanced enough and there are no measurements for UE position. On the other hand for UMTS/HSPA the UE positioning measurements could be used to report the exact location at the point of measurements. There are some discussions for enhancing the LTE measurements to include the longitude, latitude, altitude, velocity and even direction (too ambitious?).

Finally it should be pointed out that UE based reporting based on the User Plane Measurements (typically done by the operator installing a small application on the handset) can be performed by the operator in case a user is reporting poor coverage or failure in an area. Since these are proprietary applications, the operator can collect variety of information including but not limited to, position information, crrent cell and neighbour cell power levels, etc.

With all the control plane measurements and user plane measurements, the battery life could be severely affected and it has to be made sure that these are done very seldomly or with users permission.

Some of the things mentioned above may not be exactly true and if you know better please feel free to correct me.

[1] 3GPP TR 36.805 - Study on Minimization of drive-tests in Next Generation Networks

[2] 3GPP TS 37.320 - Universal Terrestrial Radio Access (UTRA) and Evolved Universal Terrestrial Radio Access (E-UTRA); Radio measurement collection for Minimization of Drive Tests (MDT); Overall description; Stage 2 (Release 10)

SON for reducing Opex in Legacy Networks

Presented by Stéphane Téral, Principal Analyst, Mobile and FMC Infrastructure, Infonetics Research in the 1st Self-Organizing Networks Conference, 30th Nov and 1st Dec. 2010 at the Waldorf Hilton.

SON Features in Legacy Networks

View more presentations from Zahid Ghadialy.

SON framework in 3GPP

From a Presentation by Cinzia Sartori from Nokia Siemens Networks (NSN) in the Self-Organising Networks Conference in London, Nov. 2010

Release 8 functionality

• Self-configuration procedures

Release 9 enhancements

• Self-optimization procedures

• Energy Saving Intra-RAT

Release 10 objectives

• Extend Self-optimization procedures , including inter-RAT

• Minimization of Drive Test (MDT)

• Energy Saving extension, including Multi-RAT (Study Item)

• 3G-ANR

• SON Conflict Resolution

SON features for R11 (Probably - Under Discussion)

• Minimization of Drive Tests (MDT) enhancements

• Mobility Robustness Optimization for MultiRAT

• SON for LTE-A features defined in Rel.10

•• Hetrogeneous Networks aka. HetNet?

•• SON for Relays

•• SON for Carrier Aggregation

Inter-Operability Testing (IOT) Process Flow

I have been asked couple of times about the IOT process, how it works, etc. The above picture is from a Huawei Presentation in "The 3GPP release 8 IMS Implementation, Deployment & Testing workshop".

You can read more about 3G/4G testing from my old article here.

Role of ENUM in NGN Interconnect

I have blogged about ENUM here and here and its been quite a while. In these last couple of years ENUM has evolved a bit and now GSMA has its own Number translation service called Pathfinder.

The following is a presentation by GSMA in the recently concluded The 3GPP release 8 IMS Implementation, Deployment & Testing workshop.

The Role of ENUM in NGN Interconnect

View more presentations from Zahid Ghadialy.

Presentation: IMS for 3G Voice Services and Migration Strategies

Very interesting presentation from NTT DoCoMo in the IMS workshop I blogged about yesterday. It shows their strategy to move from legacy core network to an All IP Network (AIPN).

IMS for 3G Voice Services and Migration Strategies

View more presentations from Zahid Ghadialy.

The 3GPP release 8 IMS Implementation, Deployment & Testing workshop

The 3GPP release 8 IMS Implementation, Deployment & Testing workshop took place in Sophia Antipolis on 24-25 November 2010.

The event was attended by 70 delegates actively participating to the discussions.

Presenting companies included: Tel : A1 Telekom Austria, Alcatel Lucent, Codenomicon, Conformiq, Eircom, Elvior, ETSI, France Telecom, GSMA, Huawei, Huawei, Mobitel, NTT DoCoMo, SFR, Telecom Italia, TestingTech, TU Berlin, Wind, Wipro, ZTE.

Here are the highlights from the ETSI document:

Goals and Outcome for this workshop

Share exprience from IMS implementation

Highlight areas for further specifications, for

Standards and Testing

Learn of issues and possible resolutions

Comments from The IMS Network Testing Group

Develop IMS core network test specifications based upon 3GPP, for:

• Interoperability

• conformance

• network integration

Hold interoperability events (IMS Plugtests)

Coordinate with other organisations such as OMA, MSF, GSMA

Implementations

• Beyond small islands, second wave to replace unscalable, unmaintenable early VoIP systems

• Implementation options - Hybrid CS-GW for transition from CS to LTE, which already has 2 million subscribers on IMS/CS-GW/RNC

• Auto provisioning - to simplify complexity

• IMS functions must be implemented in the core – not in any access network, such as LTE, and can be used for non-Voice as well

Implementing RCS (Rich Communication Suite)

• RCS trial feedback - Good feedback from 400 trial users on RCS but difficult to configure SBC

• RCS implementations should include aggregation with SNS (Social Network Services)– eg contact list from Facebook

• Most appreciated feature of RCS is: - cross-operator interworking and compatibility with ordinary phones, not just smartphones

Specific Issues and Resolutions

• FAX – Delay and Jitter issues - FTTH will solve long delays etc

• Emergency and Lawful Intercept with IMS -There are standards and developed solutions available but Currently still falls back to CS /TDM

• Data Provisioning speed is important, to achieve no service interruption.

• 3GPP II-NNI: Inter-IMS Network to Network Interface - Two levels: Solx (service with control function) and Coix (connection – a pipe for media).

• “PathFinder” Global ENUM – like DNS for phone number; It is a solution to number portability and can optimise routing

About Services

• Most issues are Beyond IMS - integrating OSS/BSS, existing systems, inter-vendors interfaces

• IMS and IN - Pity the Standards did not bring IN and IMS close together; Need iFC enhancements, like in IN; Need to support combining services

• OTT and SNS dominate growth - occupies the minds of commercial people, GSMA-like services have slowed down

• Service layer (Wipro) – Telcos want one SDP to serve all - include IMS and non-IMS services, human and non-humans on NAB, context based, and charge only what is ‘consumed’

Testing Methods, Tools and Test Beds

• Integrate Conformance checking with interoperability testing

• Automation of interoperability trace checking – it can reduce costs by more than 50 % compared to manual validation

• Independent Test Bed- available EPC playground for prototyping applications

• Protocol message customisation tool - allows changing the message and customise the flow

• Security testing tool - testing by ‘fuzzing’, 100% TTCN free – everything is already build in

• IMS is a multi vendor environment - Testing and validation must be an integral part of the deployment process

Memorable Quotes

“IMS is a Journey, not a destination” (ALU)

“SDP is almost anything” (Matjas Bericic, Mobitel)

“Voice as an app versus Voice as a Service” is a challenge (Manuel Vexler, Huawei)

“IMS is not a box, it is a network” (Matjas Bericic, Mobitel)

“global ENUM is DNS for phone numbers” (Adrian Dodd, GSMA)

“Kill with one SIP” (Ari Takanen, Codenomicon)

“ IOP is the red thread running through the entire ETSI standards development process “ (Milan Zoric, ETSI)

All documents from this workshop is available at: http://docbox.etsi.org/Workshop/2010/201011_IMSWORKSHOP/