3gLteInfo

LTE And LTE Advanced Cell Selection Procedure

3gLteInfo — Tue, 10 Apr 2012 14:35:48 +0000

The principles of PLMN selection in E-UTRA are based on the 3GPP PLMN selection principles. Cell selection is required on transition from EMM_DETACHED to EMM-REGISTERED and from ECM-IDLE or ECM-CONNECTED.

Cell selection

The UE NAS layer identifies a selected PLMN and equivalent PLMNs

The NAS can control the RAT(s) in which the cell selection should be performed, for instance by indicating RAT(s) associated with the selected PLMN, and by maintaining a list of forbidden registration area(s) and a list of equivalent PLMNs. The UE shall select a suitable cell based on idle mode measurements and cell selection criteria.

The UE searches the E-UTRA frequency bands and for each carrier frequency identifies the strongest cell. It reads cell system information broadcast to identify its PLMN(s)

The UE may search each carrier in turn (“initial cell selection”) or make use of stored information to shorten the search (“stored information cell selection”).

The UE seeks to identify a suitable cell; if it is not able to identify a suitable cell it seeks to identify an acceptable cell. When a suitable cell is found or if only an acceptable cell is found it camps on that cell and commence the cell reselection procedure

A suitable cell is one for which the measured cell attributes satisfy the cell selection criteria; the cell PLMN is the selected PLMN, registered or an equivalent PLMN; the cell is not barred or reserved and the cell is not part of a tracking area which is in the list of “forbidden tracking areas for roaming”
An acceptable cell is one for which the measured cell attributes satisfy the cell selection criteria and the cell is not barred

Transition to RRC_IDLE

On transition from RRC_CONNECTED to RRC_IDLE, a UE should camp on the last cell for which it was in RRC_CONNECTED or a cell/any cell of set of cells or frequency be assigned by RRC in the state transition message.

Recovery from out of coverage

The UE should attempt to find a suitable cell in the manner described for stored information or initial cell selection above. If no suitable cell is found on any frequency or RAT the UE should attempt to find an acceptable cell.

Cell Selection Process

Initial Cell Selection

This procedure requires no prior knowledge of which RF channels are E-UTRA carriers. The UE shall scan all RF channels in the E-UTRA bands according to its capabilities to find a suitable cell. On each carrier frequency, the UE need only search for the strongest cell. Once a suitable cell is found this cell shall be selected.

Stored Information Cell Selection

This procedure requires stored information of carrier frequencies and optionally also information on cell parameters, from previously received measurement control information elements or from previously detected cells. Once the UE has found a suitable cell the UE shall select it. If no suitable cell is found the Initial Cell Selection procedure shall be started.

Cell Selection Criterion

The cell selection criterion S is fulfilled when:

Srxlev > 0 AND Squal > 0

Where:

Srxlev = Qrxlevmeas – (Qrxlevmin + Qrxlevminoffset) – Pcompensation

Squal = Qqualmeas – (Qqualmin + Qqualminoffset)

Where:

Srxlev	Cell selection RX level value (dB)
Squal	Cell selection quality value (dB)
Qrxlevmeas	Measured cell RX level value (RSRP)
Qqualmeas	Measured cell quality value (RSRQ)
Qrxlevmin	Minimum required RX level in the cell (dBm)
Qqualmin	Minimum required quality level in the cell (dB)
Qrxlevminoffset	Offset to the signalled Qrxlevmin taken into account in the Srxlev evaluation as a result of a periodic search for a higher priority PLMN while camped normally in a VPLMN
Qqualminoffset	Offset to the signalled Qqualmin taken into account in the Squal evaluation as a result of a periodic search for a higher priority PLMN while camped normally in a VPLMN
Pcompensation	max(PEMAX –PPowerClass, 0) (dB)
PEMAX	Maximum TX power level an UE may use when transmitting on the uplink in the cell (dBm)
PPowerClass	Maximum RF output power of the UE (dBm) according to the UE power class

References

Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network
(E-UTRAN); Overall description; Stage 2: 3GPP TS 36.300
Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) procedures in idle mode : 3GPP TS 36.304

The 5 Best LTE And LTE-Advanced Books

3gLteInfo — Thu, 01 Mar 2012 11:44:04 +0000

Did you ever struggle to read the 3GPP LTE and LTE Advanced from the standards directly? Some time its very hard to go through many specifications to find out simple things. As the 3GPP specifications are interlinked together and contents tons of information it is always good to follow a book.

Because LTE and LTE Advanced is the technology which will drive the future of mobile communication it is always good to have better knowledge on these.

Here is a list of books which you should use to refine your knowledge on LTE and LTE Advanced.

1. 4G: LTE/LTE-Advanced for Mobile Broadband

This book focuses on LTE with full updates including LTE-Advanced to provide a complete picture of the LTE system. Overview and detailed explanations are given for the latest LTE standards for radio interface architecture, the physical layer, access procedures, broadcast, relaying, spectrum and RF characteristics, and system performance.

Key technologies presented include multi-carrier transmission, advanced single-carrier transmission, advanced receivers, OFDM, MIMO and adaptive antenna solutions, advanced radio resource management and protocols, and different radio network architectures. Their role and use in the context of mobile broadband access in general is explained.
Both a high-level overview and more detailed step-by-step explanations of the LTE/LTE-Advanced implementation are given. An overview of other related systems such as GSM/EDGE, HSPA, CDMA2000, and WIMAX is also provided.
Includes full details of the latest additions to the LTE Radio Access standards and technologies up to and including 3GPP Release 10
Clear explanations of the role of the underlying technologies for LTE, including OFDM and MIMO
Full coverage of LTE-Advanced, including LTE carrier aggregation, extended multi-antenna transmission, relaying functionality and heterogeneous deployments
LTE radio interface architecture, physical layer, access procedures, MBMS, RF characteristics and system performance covered in detail

Buy it here:

4G: LTE/LTE-Advanced for Mobile Broadband

2. LTE – The UMTS Long Term Evolution: From Theory to Practice

The book highlights practical implications, illustrates the expected performance, and draws comparisons with the well-known WCDMA/HSPA standards. The authors not only pay special attention to the physical layer, giving an insight into the fundamental concepts of OFDMA-FDMA and MIMO, but also cover the higher protocol layers and system architecture to enable the reader to gain an overall understanding of the system.

Comprehensively updated with the latest changes of the LTE Release 8 specifications, including improved coverage of Radio Resource Management RF aspects and performance requirements
Provides detailed coverage of the new LTE Release 9 features, including: eMBMS, dual-layer beamforming, user equipment positioning, home eNodeBs / femtocells and pico cells and self-optimizing networks
Evaluates the LTE system performance
Introduces LTE-Advanced, explaining its context and motivation, as well as the key new features including: carrier aggregation, relaying, high-order MIMO, and Cooperative Multi-Point transmission (CoMP).
Includes an accompanying website containing a complete list of acronyms related to LTE and LTE-Advanced, with a brief description of each.

Buy it here:

LTE – The UMTS Long Term Evolution: From Theory to Practice

3. LTE for UMTS: Evolution to LTE-Advanced

This new edition also provides an outlook to Release 10, including the overview of Release 10 LTE-Advanced technology components which enable reaching data rates beyond 1 Gbps.
Key updates for the second edition of LTE for UMTS are focused on the new topics from Release 9 & 10, and include:
LTE-Advanced;

Self optimized networks (SON);
Transport network dimensioning;
Measurement results.

Buy it here:
LTE for UMTS: Evolution to LTE-Advanced

4. LTE Signaling: Troubleshooting and Optimization

DO you work more on the call flows and signalling side of LTE then this book for you.

This book supplements the information provided in the 3GPP standards by giving readers access to a universal LTE/EPC protocol sequence to ensure they have a clear understanding of the issues involved. It describes the normal signaling procedures as well as explaining how to identify and troubleshoot abnormal network behavior and common failure causes.

Enables the reader to understand the signaling procedures and parameters that need to be analyzed when monitoring UMTS networks
Covers the essential facts on signaling procedures by providing first hand information taken from real LTE/EPC traces
A useful reference on the topic, also providing sufficient details for test and measurement experts who need to analyze LTE/EPC signaling procedures and measurements at the most detailed level
Contains a description of LTE air interface monitoring scenarios as well as other key topics up to an advanced level

Buy it here:
LTE Signaling: Troubleshooting and Optimization

5. SAE and the Evolved Packet Core: Driving the Mobile Broadband Revolution

This book provides a clear, concise, complete and authoritative introduction to System Architecture Evolution (SAE) standardization work and its main outcome: the Evolved Packet Core (EPC), including potential services and operational scenarios. After providing an insightful overview of SAE’s historical development, the book gives detailed explanations of the EPC architecture and key concepts as an introduction. In-depth technical descriptions of EPC follow, including thorough functional accounts of the different components of EPC, protocols, network entities and procedures.

Up-to-date coverage of SAE including the latest standards development
Easily accessible overview of the architecture and concepts defined by SAE
Thorough description of the Evolved Packet Core for LTE, fixed and other wireless accesses
Comprehensive explanation of SAE key concepts, security and Quality-of-Service
Covers potential service and operator scenarios including interworking with existing 3GPP and 3GPP2 systems
Detailed walkthrough of network entities, protocols and procedures
Written by established experts in the SAE standardization process, all of whom have extensive experience and understanding of its goals, history and vision

Buy it here:

SAE and the Evolved Packet Core: Driving the Mobile Broadband Revolution

Write your reviews on the books.

LTE And LTE Advanced Frequency Bands And Spectrum Alloactions

3gLteInfo — Fri, 24 Feb 2012 18:19:38 +0000

The LTE frequency bands in 3GPP standards are divided into paired bands and unpaired bands. Some of the bands are presently used by other technologies and LTE can coexist with the legacy technologies.

In the best case in Europe there is over 600MHz of spectrum available for the mobile operators when including the 800, 900, 1800, 2100 and 2600MHz Frequency Division Duplex (FDD) and Time Division Duplex (TDD) bands.

In the USA the LTE networks will initially be constructed on 700 and 1700/2100 MHz frequencies. In Japan the LTE deployments begin using the 2100 band followed later by 800, 1500 and 1700 bands.

Flexible bandwidth is desirable to take benefit of the diverse spectrum assets: refarming typically requires a narrowband option below 5MHz while the new spectrum allocations could take advantage of a wideband option of data rates of 20MHz and higher.

It is also evident that both FDD and TDD modes are required to take full advantage of the available paired and unpaired spectrum. These requirements are taken into account in the LTE system specification.

LTE and LTE Advanced Frequency Bands Allocations

Frequency Band	E UTRA Operating Band Uplink (UL) operating band BS receive UE transmit FUL_low – FUL_high	Downlink (DL) operating band BS transmit UE receive FDL_low – FDL_high	Duplex Mode	Regions
1	1920 MHz – 1980 MHz	2110 MHz – 2170 MHz	FDD	Japan, Europe, Asia
2	1850 MHz – 1910 MHz	1930 MHz – 1990 MHz	FDD	Canada, US, Latin America
3	1710 MHz – 1785 MHz	1805 MHz – 1880 MHz	FDD	Finland, Hong Kong, Germany, Poland
4	1710 MHz – 1755 MHz	2110 MHz – 2155 MHz	FDD	Canada, US (T-Mobile), Latin America
5	824 MHz – 849 MHz	869 MHz – 894MHz	FDD	Canada, US, Australia, Latin America
6	830 MHz – 840 MHz	875 MHz – 885 MHz	FDD	Japan
7	2500 MHz – 2570 MHz	2620 MHz – 2690 MHz	FDD	EU, Latin America
8	880 MHz – 915 MHz	925 MHz – 960 MHz	FDD	EU, Latin America
9	1749.9 MHz – 1784.9 MHz	1844.9 MHz – 1879.9 MHz	FDD	Japan
10	1710 MHz – 1770 MHz	2110 MHz – 2170 MHz	FDD	Uruguay, Ecuador, Peru
11	1427.9 MHz – 1447.9 MHz	1475.9 MHz – 1495.9 MHz	FDD	Japan (Softbank, KDDI, DoCoMo)
12	699 MHz – 716 MHz	729 MHz – 746 MHz	FDD	US
13	777 MHz – 787 MHz	746 MHz – 756 MHz	FDD	US (Verizon)
14	788 MHz – 798 MHz	758 MHz – 768 MHz	FDD	US
15	Reserved	Reserved	FDD
16	Reserved	Reserved	FDD
17	704 MHz – 716 MHz	734 MHz – 746 MHz	FDD	US (AT&T)
18	815 MHz – 830 MHz	860 MHz – 875 MHz	FDD
19	830 MHz – 845 MHz	875 MHz – 890 MHz	FDD
20	832 MHz – 862 MHz	791 MHz – 821 MHz	FDD	EU
21	1447.9 MHz – 1462.9 MHz	1495.9 MHz – 1510.9 MHz	FDD
22	3410 MHz – 3490 MHz	3510 MHz – 3590 MHz	FDD
23	2000 MHz – 2020 MHz	2180 MHz – 2200 MHz	FDD
24	1626.5 MHz – 1660.5 MHz	1525 MHz – 1559 MHz	FDD
25	1850 MHz – 1915 MHz	1930 MHz – 1995 MHz	FDD	US (Sprint)
…
33	1900 MHz – 1920 MHz	1900 MHz – 1920 MHz	TDD
34	2010 MHz – 2025 MHz	2010 MHz – 2025 MHz	TDD
35	1850 MHz – 1910 MHz	1850 MHz – 1910 MHz	TDD
36	1930 MHz – 1990 MHz	1930 MHz – 1990 MHz	TDD
37	1910 MHz – 1930 MHz	1910 MHz – 1930 MHz	TDD
38	2570 MHz – 2620 MHz	2570 MHz – 2620 MHz	TDD	EU
39	1880 MHz – 1920 MHz	1880 MHz – 1920 MHz	TDD
40	2300 MHz – 2400 MHz	2300 MHz – 2400 MHz	TDD	China, India, Australia
41	2496 MHz 2690 MHz	2496 MHz 2690 MHz	TDD	US (Clearwire)
42	3400 MHz – 3600 MHz	3400 MHz – 3600 MHz	TDD
43	3600 MHz – 3800 MHz	3600 MHz – 3800 MHz	TDD

Note: Band 6 is not applicable

Is LTE 4G? What is difference between LTE and LTE Advanced?

3gLteInfo — Thu, 23 Feb 2012 21:54:41 +0000

The Long-Term Evolution (LTE) is often called “4G”, but many also claim that LTE release 10, also known to as LTE-Advanced, is the true 4G evolution step, with the first release of LTE ( Release 8 ) then being labeled as “3.9G”.

This ongoing race of increasing sequence numbers of mobile system generations is in fact just a matter of labels. What is essential is the actual system capabilities and how they have advanced.

The evolution of 3G systems into 4G is powered by the creation and growth of new services for mobile devices, and is enabled by advancement of the technology available for mobile systems. There has also been an evolution of the environment in which mobile systems are deployed and operated, in terms of levels of competition between mobile operators, challenges from other mobile technologies, and new regulation of spectrum use and market aspects of mobile systems.

Fixed telephony (POTS) and earlier generations of mobile technology were developed for circuit switched services, primarily voice. The first data services over GSM were circuit switched, with packet-based GPRS following in as a later addition. This also affected the first development of 3G,which was primarily based on circuit switched data, with packet-switched services as an add-on. It was not until the 3G evolution into HSPA and later LTE/LTE-Advanced that packet-switched services and IP were made the primary design target. The old circuit-switched services remain, but will on LTE be provided over IP, with Voice-over IP (VoIP) as an example.

IP is in itself service agnostic and thereby enables a range of services with different requirements.The main service-related design parameters for a radio interface supporting a variety of services are:

Data rate: Many services with lower data rates such as voice services are important and still occupy a large part of a mobile network’s overall capacity, but it is the higher data rate services that drive the design of the radio interface. The ever increasing demand for higher data rates for web browsing, streaming and file transfer forces the peak data rates for mobile systems from kbit/s for 2G, to Mbit/s for 3G and getting close to Gbit/s for 4G.

Delay: Interactive services such as real-time gaming, but also web browsing and interactive file transfer, have requirements for very low delay, making it a primary design target. There are, however, many applications such as e-mail and television where the delay requirements are not as strict. The delay for a packet sent from a server to a client and back is called latency.

Capacity: From the mobile system operator’s point of view, it is not only the peak data rates provided to the end-user that are of importance, but also the total data rate that can be provided on average from each deployed base station site and per hertz of licensed spectrum. This measure of capacity is called spectral efficiency. In the case of capacity shortage in a mobile system, the Quality-of-Service (QoS) for the individual end-users may be degraded.

What is the motivation behind LTE?

LTE must be able to deliver performance superior to that of existing 3GPP networks based on HSPA technology. The performance targets in 3GPP are defined comparable to HSPA in Release 6. The peak user throughput should be a minimum of 100 Mbps in the downlink and 50 Mbps in the uplink, which is ten times more than HSPA Release 6.

The main performance targets are:

spectral efficiency two to four times more than with HSPA Release 6;
peak rates surpass 100 Mbps in the downlink and 50 Mbps in the uplink;
allows a round trip time of
packet switched enhanced;
high level of mobility and security;
enhanced terminal power efficiency;
frequency versatility with allocations from below 1.5MHz up to 20 MHz.

What is LTE Advanced?

International Mobile Telecommunications – Advanced (IMT-Advanced) is a concept for mobile systems with capabilities beyond IMT-2000. IMT-Advanced was formerly known as ‘Systems beyond IMT-2000’. The candidate recommendations for IMT-Advanced were submitted to ITU in 2009. Only two candidates were submitted: LTE-Advanced from 3GPP and IEEE 802.16m.

It is envisaged that the new features of these IMT-Advanced systems will allow a wide range of data rates in multi-user environments with target peak data rates of up to approximately 100 Mbps for high mobility requirements and up to 1 Gbps for low mobility requirements such as nomadic/local wireless access. IMT-Advanced function within 3GPP is called LTE-Advanced (LTE-A) and it is part of Release 10. 3GPP submitted an LTEAdvanced proposal to ITU in October 2009 and more detailed work was done during 2010.

The content material was frozen in December 2010 and the backwards compatibility in June 2011.

The main technology elements in Release 10 LTE-Advanced include:

carrier aggregation up to 40MHz total band, and later on potentially up to 100 MHz;
MIMO evolution up to 8 × 8 in downlink and 4 × 4 in uplink;
relay nodes for offering simple transmission solution;
heterogeneous networks for optimized interworking between cell layers including macro, micro, pico and femto cells.

LTE-Advanced features are designed in a backwards-compatible way where LTE Release 8 devices can be used on the same carrier where new LTE-Advanced Release 10 features are activated.

Best Free Resources To Learn 3GPP LTE

3gLteInfo — Fri, 03 Feb 2012 10:40:36 +0000

Either you are a 3G, LTE or LTE Advanced developer or a tester you will definitely love to have these free study materials and Webcast CDs from Agilent. If you do not know about Agilent, it is one of the biggest wireless test equipments manufacturer in the world.

Agilent is specialized in range of products staring from Oscilloscopes, Protocol Analyzers, Network Analyzers, Bit Error Ratio Test Solutions, EMI/EMC, Phase Noise, Physical Layer Test Systems and many other important test and debugging products.

This free study materials from Agilet includes

Posters on Mobile Computing Interfaces Architecture, Evolving Wireless Standards, Understanding the Intricacies of LTE, Ten Things You Should Know About MIMO.

Free LTE Webcast CDs of

LTE Design & Test Fundamentals Volume 1
- Addressing the Design & Verification Challenges of 3GPP LTE
- Understanding SC-FDMA – The New LTE Uplink
- LTE Protocol Primer • RF Measurements for LTE
- LTE Protocol Control and Signaling
LTE Design & Test Fundamentals Volume 2
- Ten Things You Should Know about MIMO
- MIMO RF Measurements – Choosing and Using Tools
- Taking LTE MIMO from Standards to Starbucks
- LTE MIMO System Level Design and Test
- Making the Journey from WiMAX to LTE
- Addressing the Design and Verification Challenges of Cognitive Radio and SDR
- Introduction to LTE Advanced
LTE Design & Test Fundamentals Volume 3
- Completing LTE eNB Closed-loop Conformance Tests
- Over-The-Air (OTA) Test Methods to Evaluate the Performance of MIMO Handsets
- How to Verify the Data in Your LTE Downlink Signal
- 4G For Everyone: Extended RF Performance with Digital Pre-Distortion
- Understanding Cross Modulation Effects in a Full Duplex LTE

Apart from that you can download App notes, Brochure and Software

MIMO in LTE Operation and Measurement–Excerpts on LTE Test
MIMO Performance and Condition Number in LTE Test
Measuring ACLR Performance in LTE Transmitters
Stimulus-Response Testing for LTE Components
Greater Insight into LTE Design and Test
Move Forward to What’s Possible in TD-LTE Design & Test Solutions
89600 VSA Software Trial CD
Signal Studio Software Trial CD

Agilent gives two options for you to get these. Either you can download or Agilent will ship all these study materials to you without any charge.

Check the below link to download or order these useful LTE resources.

https://www.home.agilent.com/agilent/editorial.jspx?cc=AD&lc=eng&ckey=1326831-1-eng&nid=-33796.0.00&id=1326831-1-eng

IP Multimedia Subsystem (IMS) Emergency Sessions – Part 1

3gLteInfo — Thu, 02 Feb 2012 11:10:56 +0000

Non Voice Emergency Service (NOVES ) allows the UE to use other media and communication types other than voice and GTT during an IMS emergency session when the network supports IMS emergency service and the UE also supports other media or communication types.

In case of Emergency session over IMS, Emergency sessions should be prioritized over non-emergency sessions by the system.

Emergency Service is not a subscription service and therefore, when the UE has roamed out of its home network, emergency services shall not be provided by the home network and shall be provided in the roamed-to network if the roamed-to network supports emergency sessions. If a UE has sufficient credentials, it shall initiate an emergency registration with the network (requiring the involvement of the home network). The CSCFs providing service for emergency sessions may be different from the CSCFs involved in the other IMS services. If the registration fails, the UE may attempt an anonymous emergency call.

When a UE performs an emergency registration, barring and roaming restrictions are ignored.

If the UE has location information available, the UE shall include the location information in the request to establish an emergency session. The location information may consist of network location information, that is the Location Identifier, and/or the Geographical location information.
The P‑CSCF may query the IP‑CAN to obtain location identifier.

In can of IMS emergency service the UE should be able to access the IP-CAN without sufficient security credentials.

IMS Emergency Service Architecture

NOTE:

P‑CSCF, EATF and E-CSCF are always located in the serving network.

Based on operator policy, the E‑CSCF can route the emergency IMS session to the PSAP via an ECS

The UE should able to detect emergency session establishment request. If an incoming call has an emergency call back indicator present, the UE shall detect the incoming PSAP call back session establishment request.

Proxy‑CSCF

Proxy‑CSCF handle registration requests with an emergency registration indication like any other registration request, except that it may reject an emergency registration request if the IM CN subsystem that the P‑CSCF belongs to can not support emergency sessions for the UE.

For non-roaming subscribers, the P-CSCF may forward an emergency session to an S-CSCF if so instructed by operator policy or local regulation.

Emergency‑CSCF

Emergency‑CSCF receives an emergency session establishment request from a P‑CSCF or an S-CSCF. If the UE does not have credentials, a non-dialable callback number shall be derived where required by local regulation.

If location information is not included in the emergency request or additional location information is required, the E‑CSCF may request the LRF to retrieve location information as described in clause 7.6 Retrieving Location information for Emergency Session.

Location Retrieval Function (LRF)

Location Retrieval Function (LRF) is responsible for retrieving the location information of the UE that has initiated an IMS emergency session.

LRF utilizes the a Routing Determination Function (RDF) to provide the routing information to the E‑CSCF for routing the emergency request.

Serving-CSCF

When the S‑CSCF receives an Emergency Registration, the S‑CSCF determine the duration of the registration by checking the value of the Expires header in the received REGISTER request and based on local regulation or operator policy of the serving system.

MGCF

The MGCF may:

Determine based on the operator policy if an incoming call form the PSTN is for the purpose of PSAP call-back. The operator policy decision may be based on that the call is from an emergency centre or from a PSAP and/or any other information made available to the MGCF.
Include a “PSAP call-back indication” in the SIP session establishment request if an incoming call is determined to be for the purpose of PSAP call-back.

Reference

3GPP 23.167 – IP Multimedia Subsystem (IMS) emergency sessions

Minimization of Drive Test Use Cases

3gLteInfo — Wed, 01 Feb 2012 08:23:28 +0000

This is the second part of the Minimization of Drive Test series. If you missed the first part check you can get it here.

Minimization Of Drive Test Requirements Analysis

In this part the main focus on different use cases where MDT can be applied.

Minimization of Drive Test (MDT) specifies different ways to improve network efficiency by using UE measurement logs. The logs collection in UE can be periodic or event triggered (e.g Radio Link Failures).

To make the MDT process more efficient and provide adequate results, different use cases are defined.

Coverage Optimization

Information about radio coverage is essential for network planning, network optimization and Radio Resource Management parameters optimization.

The coverage optimization of the network is required in the following cases.

Deployment of new base stations cells

When new base stations or cells are deployed, drive tests are performed before and after the service deployment. When initially the radio waves are transmitted the cell is barred from normal use. (This is done through setting barred information in SIB 3).

But after the initial tests are over and the cell is made available for normal use, the operators does drive test to collect more extensive data of UL/DL coverage measurement to make sure the location under test provides goof UL/DL coverage.

Construction of new highways, railways or major buildings

Areas where new highways / railways / major buildings are constructed are potential areas which residing population will increase, and are important areas to provide good coverage. Also, such large constructions normally introduce weak pilot areas as they become new sources of shadowing losses.

Customer’s complaints

Customer’s complaints are an important trigger to perform drive tests. When customers indicate coverage / throughput concerns (e.g. poor DL coverage at their home, office, etc.), operators perform “drive tests” in the relevant area to observe the coverage quality.

Periodic drive tests

This is the additional phase of drive test that is performed for a particular cell / smaller network area or the entire network in a regular and on demand manner.

Mobility optimization

Information about mobility problems or failures can be used to identify localized lack of coverage or the need to adapt the network parameters setting, e.g. in order to avoid too early or too late handover and to improve the handover success rate and overall network performance.

Capacity optimization

The operator needs to be able to determine if there is too much/little capacity in certain parts of the network i.e. to detect locations where e.g. the traffic is unevenly distributed or the user throughput is low. This helps to e.g. determine placement of new cells, configure common channels and optimize other capacity related network parameters.

Parametrization of common channels

User experience and/or network performance can be degraded by suboptimal configuration of common channels (e.g. random access, paging and broadcast channels).

QoS verification

This aspect is important also in the initial deployment of a new radio access technology, in order to check if the quality of service experienced by the end user is in line with the performance target defined in the planning strategy and more in general to test the overall performance of the technology along the subsequent deployment phases.

Summery

In the coming parts there will be some more articles on Minimization of Drive Test, the patents related to the technology and what can be the future of this.

References

3GPP TR 36.805 – Study on Minimization of drive-tests in Next Generation Networks
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)