LTE Protocol Stack
Accelerate your mobile technology
LTE Protocol Stack Fast • Portable • Customisable
LTE Protocol Stack The UMTS-LTE (Long Term Evolution) Protocol Stack has been created using knowledge gained from our long experience in the definition and development of mobile network standards. It is an implementation of the core stack that is ready for integration into your next LTE development and is the latest in a long line of mobile technology created at Roke Manor. Our protocol stack runs in a live environment to demonstrate a truly mobile all-IP network. The demonstration of the prototype includes internet browsing, a live VoIP call and seamless handover.
Technical description The protocol elements and their location in the hierarchy are shown in the protocol stack Figure 1. Application layer • AV Streaming • Web Browsing
UE
S1 and X2 • Simplified GTP-U for U-plane data • SCTP for assured C-Plane messages • S1AP, X2AP: A functional emulation of the S1 and X2 Application Protocols which mimics anticipated message flows and message fields using simpler software structures but avoiding the complexities of a full ASN.1 implementation. eUU: • PD including Header Compression and Encryption • RLC, based on earlier UMTS implementation • MAC with fair downlink scheduling working with LTE resource structures. • A pseudo Layer 1/Layer 2 is used to emulate the air interface whilst utilising the LTE resource structures thus avoiding the need to emulate Layer 1 in testbed developments. Interfacing to a real Layer1 can be achieved without re-design of the lower layers.
eNB
MME NAS Signalling Protocols (including security)
NAS Signaling Protocols (including security) RRC
RRC
PD
PD
RLC
RLC MAC
MAC
PHY
PHY
S1-Application Protocol (S1-AP)
S1-Application Protocol (S1-AP)
SCTP
SCTP
IPSec
IPSec
IP inc. Diffserv
IP inc. Diffserv
Data Link Layer 2
Data Link Layer 2 PHY Layer 1
PHY Layer 1 LT -Uu
S1-MME
Control Plane Protocols UE
eNB
S-GW
PDN-GW
End
Appl.
Appl.
Transport Protocols
Transport Protocols (inc IP) PD
PD
GTP-U
GTP-U
RLC
RLC
UDP
MAC
MAC
IP inc Diffserv
PHY
PHY
UDP
IP Sec
IP Sec IP inc Diffserv
PIMP GTP-U
UDP IP Sec
UDP IP Sec
IP inc Diffserv
IP inc Diffserv
Data Link Data Link
Data Link PHY
LTE-Uu
PIMP GTP-U
PHY S1-U
Data Link PHY
PHY S 5/S 8
Plane Protocols
Figure 1. LTE Protocol Stack
Data Link
PHY
PHY
Further Development Roap Our LTE protocol stack implementation timeline has been designed to provide essential functionality as early as possible and hence to allow for early application development. The core elements of the stack at Layer 2 and above were the primary focus of development in order to allow UE handover between eNodeBs. Subsequent development has transitioned the protocol stack to a more fully compliant solution as the LTE standard has been refined by 3GPP. Work is continuing to extend the compliance of the Roke LTE protocol stack to include functionality for interworking with other RATs (such as UTRAN, CDMA2000 and GPRS) and the optional elements as defined by test priorities currently under discussion by RAN WG5 of 3GPP.
HARQ
Header Compression
Dynamic Scheduling
Intra-LTE Handover
Security Establishment
Inter-LTE Handover
PD/RLC/MAC Data Transfer
UE Capabilities
Core stack
Enhanced stack
Full standards compliance
Complete stack
Time
Figure 2. Roke LTE Stack Road Map
Some of the most important stage features are shown in Figure 2. A complete list is available separately – us for details.
Background Over many years Roke has gained extensive experience in emerging telecommunication technologies, from original research and standards development to rapid development of demonstration prototypes right through to the development and testing of production prototypes. We were one of the first companies in the world to build a GSM demonstrator and have played a similar leading role in the development of 3G systems. Specific examples include: • a 3rd Generation test bed enabling the very first remote TDD phone call in the 1990’s • an environment to test 3rd generation RNC U-Plane performance at full load • Acceptance testing on the RNC • FDD Node B development • Femto Node B evealuation As a result we have extensive knowledge of mobile system standards and many years experience in the development of systems based on those standards. LTE forms the upgrade path from the existing UMTS/3G system and provides many advantages to network operators and the end through increased efficiency and improved data rates.
Our protocol stack runs in a live environment to demonstrate a truly mobile all-IP network. The demonstration of the prototype includes internet browsing, a live VoIP call and seamless handover. We work very closely with our clients and at all times respect absolutely their confidentiality, so much so that they often consider their dedicated Roke team to be an extension of their own development group.
50 years of Innovation@Roke
To discuss how this capability can be integrated into your platform us by using the details below
For further information please : Elaine Burroughs T +44 (0)1794 672898 F +44 (0)1794 833433
[email protected] www.roke.co.uk
Roke Manor Research Limited Roke Manor, Romsey, Hampshire SO51 0ZN UK T +44 (0)1794 833000 F +44 (0)1794 833433
[email protected] www.roke.co.uk © Roke Manor Research Limited 2008. All rights reserved. This publication is issued to provide outline information only, which (unless agreed by the company in writing) may not be used, applied or reproduced for any purpose or form part of any order or contract or be regarded as representation relating to the products or services concerned. The company reserves any right to alter without notice the specification, design, or conditions of supply of any product or service. This is a published work the copyright in which vests in Roke Manor Research Ltd. Export of this product may be subject to UK export license approval. 0083