Tuesday, July 28, 2009

3GPP Technology Approaches for Maximizing Fragmented Spectrum Allocations

In a recently published white paper 3G Americas has offered key recommendations for utilizing non-standard spectrum bands to accommodate the growing bandwidth demands of consumers.

Whitepaper provides a overview of global spectrum allocations for 3GPP based technologies and illustrates some of the key challenges for optimal spectrum utilization when allocations differ either on a country- or region-specific basis.

While covering widely held tenets considered fundamental for sound spectrum policy it discusses current approaches to addressing fragmented spectrum challenges.

In concluding remarks 3G Americas states that that there is a significant impact of fragmented spectrum allocations on the cost and performance of mobile devices. These impacts hold true in virtually every corner of the globe.

Regulators have an important and challenging role in obtaining addition spectrum and bringing it to market to meet the demands of consumers.

3G Americas offered regulators to consider following while working on obtaining addition spectrum:

1. Spectrum should be harmonized and coordinated to the maximum extent feasible;
2. New spectrum should facilitate access by new technologies of all stripes;
3. At the same time, appropriate protections should be established for incumbent and/or adjacent service providers to protect against interference;
4. Spectrum policy should foster as far as possible the efficient use of spectrum; and
5. The rules covering the allocation, auction and deployment of spectrum should be predictable and transparent, prior to auctions.

For further reading download whitepaper.

Thursday, July 23, 2009

MIMO Transmission Schemes for LTE and HSPA Networks

3G Americas has recently published an report: MIMO Transmission Schemes for LTE and HSPA Networks. The report is intended increases awareness and helps guide the deployment of MIMO technology in HSPA and LTE networks.

Multiple-input multiple-output (MIMO) technology is commonly defined as, the use of two or more unique radio signals, in the same radio channel, where each signal carries different digital information, or two or more radio signals that use beam forming, receive combining and spatial multiplexing (SM).

This report provides the principles behind smart antenna technologies such that the reader will be able to understand the fundamental tradeoffs. Report inludes many antenna configurations that can support a wide range of MIMO algorithms at the base station as well as extensively treat the issues behind the antenna configurations at the terminal. Report addresses the specific schemes selected by 3GPP to provide smart antenna capabilities in HSPA and LTE Rel-8.

Further it focuses on the expected standardization outcome in Rel-9 and Rel-10 and more specifically, in enhancements behind clustered linear arrays (CLA) and collaborative multipoint transmission/reception (CoMP) schemes. In addition it provides performance results for a wide variety of channel conditions, and antenna configurations for both DL and UL.

Based on simulation results presented in this report, it was shown that the relatively simple MIMO transmission scheme based on 2x2 CL SM, at low user equipment (UE) speeds can increase by 20% the DL sector spectral efficiency relative to a single antenna transmission, as well as increase the cell edge efficiency by approximately 35%.

Saturday, July 18, 2009

LTE Security Principles

The following are some of the principles of 3GPP E-UTRAN security based on 3GPP Release 8 specifications:

  • The keys used for NAS and AS protection shall be dependent on the algorithm with which they are used.
  • The eNB keys are cryptographically separated from the EPC keys used for NAS protection (making it impossible to use the eNB key to figure out an EPC key).
  • The AS (RRC and UP) and NAS keys are derived in the EPC/UE from key material that was generated by a NAS (EPC/UE) level AKA procedure (KASME) and identified with a key identifier (KSIASME).
  • The eNB key (KeNB) is sent from the EPC to the eNB when the UE is entering ECM-CONNECTED state (i.e. during RRC connection or S1 context setup).
  • Separate AS and NAS level security mode command procedures are used.
  • Keys stored inside eNBs shall never leave a secure environment within the eNB (except when done in accordance with this or other 3GPP specifications), and user plane data ciphering/deciphering shall take place inside the secure environment where the related keys are stored.
  • Key material for the eNB keys is sent between the eNBs during ECM-CONNECTED intra-E-UTRAN mobility.

The figure above depicts simplified key derivation.

The MME invokes the AKA procedures by requesting authentication vectors to the HE (Home environment) if no unused EPS authentication vectors have been stored.

The HE sends an authentication response back to the MME that contains a fresh authentication vector, including a base-key named KASME. Thus, as a result of an AKA run, the EPC and the UE share KASME.

From KASME, the NAS keys, (and indirectly) KeNB keys and NH are derived. The KASME is never transported to an entity outside of the EPC, but KeNB and NH are transported to the eNB from the EPC when the UE transitions to ECM-CONNECTED.

From the KeNB, the eNB and UE can derive the UP and RRC keys.

Tuesday, July 14, 2009

3GPP Release 10 Features

3GPP Release 10 Features detailed in 3GPP description document "Overview of 3GPP Release 10; Summary of all Release 10 Features (Release 10)" are as following
  • Network Selection for non-3GPP Access
  • Registration in Densely-populated area
  • Enhanced Home NodeB / eNodeB continuation of Rel-9
  • IMS aspects of Architecture for Home NodeB - moved from Rel-9
  • IMS Service Continuity – Inter Device Transfer enhancements (EHNB)
  • GTP-based S8 chaining - moved from Rel-9
  • Multi Access PDN Connectivity - moved from Rel-9
  • EEA3 and EIA3 (new Encryption & Integrity EPS security algorithms)
  • Study on Mobile Haptic Services
  • Study on advanced requirements for IP interconnect - moved from Rel-9
  • Study on Unauthenticated PS Emergency Calls - moved from Rel-9
  • Study on Study on Personal Broadcast Service - moved from Rel-9
  • Study on LCS support in SAE for non-3GPP accesses - moved from Rel-9
  • Study on System enhancements for the use of IMS services in local breakout and optimal routing of media - moved from Rel-9
  • Study on Intra Domain Connection of RAN Nodes to Multiple CN Nodes - moved from Rel-9
  • Study on IMS Evolution - moved from Rel-9
  • Study on enhancements to IMS border functions for IMS Interconnection of services - moved from Rel-9
  • Study on Policy solutions and enhancements
  • Study on IPv6 Migration
  • Study on SR-VCC Enhancements

Tuesday, July 7, 2009

Value-added services in LTE

Mobile value-added services (VAS) are those services that are not part of the basic voice offer and are availed off separately by the end user. They are used as a tool for differentiation and allow the mobile operators to develop another stream of revenue.

Once operator start migrating towards LTE then what will be the shape of VAS? It would be interesting to see how current VAS infrastructure will be reused. VoLGA seems to be a bridging the gap during migration but what would be final implementation?

read more at LteWorld

LTE needs VoLGA

LTE (Long Term Evolution) is a data only technology but it seems that we can not live without voice or SMS services. VoLGA forum claims that VoLGA specifications fill this gap. A number of telecom companies (including Ericsson, Alcatel-Lucent, Huawei) are showing interest in VoLGA and are part of VoLGA forum.

According VoLGA stage 1 specification, The aim of VoLGA is to make traditional GSM/UMTS circuit switched (CS) services available to UEs accessing the EPS network via E-UTRAN.

The lack of native SMS over LTE support is a show-stopper for LTE dongle service. Mobile operators rely on SMS for back office customer care, provisioning and management of HSPA-dongle services. Clearly those systems need to be available to an LTE-based terminal service at launch.

read more at LteWorld

What is LTE

Nicole talks to James Orr from Fujitsu and learns about LTE. Visit LteWorld to know more about LTE.

About LteWorld

Long Term Evolution (LTE) is one of the leading next-generation wireless technologies. LTE is initiated by 3GPP to improve the mobile phone standard to cope with future technology evolutions and needs. LteWorld is created for a one-stop online destination for everything about LTE.

LteWorld is powered by NgnGuru Solutions Pvt. Ltd., a training and services company focused on telecom technologies and offers a wide range of courses appropriate for audiences needing a high-level overview, as well as engineers looking of in-depth details.