Seamless WLAN off-load of 3GPP

Introduction

The main goal of this project is to investigate abilities for seamless WLAN off-loading of 3GPP networks. It implies theoretical and practical investigation, such as abstract mathematical model, simulations, field testing and so on. We need to figure out how these networks could be used simultaneously and which characteristics they have.

Project stages

• Investigation
  At this stage, we are studying simple offload scenarios using both simulation (in a custom version of ns-2 network simulator) and a testbed.
  Theoretical questions are also addressed at this stage.
  The main points of investigation are:
  • building a network to study off-load, which uses a WLAN access point and establishes connection over IPSec tunnel;
  • simulation of Proxy Mobile IPv6 protocol, which is primarily used for WLAN-WLAN and 3G-WLAN handover;
  • simulation of handover from 3G to WLAN and back, using procedures outlined in 3GPP specifications;
  • development of network fitness function f[N], which would help choose the best network to off-load the traffic;
  • simulation of 3G-WLAN off-load using the network fitness function.

  Start Date: March 2010
  Target Date: January/February 2011

• Implementation
  This stage involves creating a working prototype of network in which seamless 3G-WLAN offload occurs, and fitness of all the networks available for offload are evaluated according to the network fitness functions.
  The prototype network would involve actual mobile devices (e.g. N900 tablet) instead of notebooks which we currently use in our testbed.
  Start Date: April 2010
  Target Date: November 2010
• Improvement and Testing
  On this stage, our developments would be tested and stressed in a real environment, and on a real device.
  Target Date: June 2011

Long-term targets

• Splitting of Traffic
  Connecting to both WLAN and 3G is permitted in 3GPP Specifications. Such connection can be used to the advantage of the mobile device's user.
  For instance, mobile node can forward all control traffic (ICMP, Routing Protos) through 3G channel, as it provides better QoS.
• Mesh Networks
  Investigation of ability to provide seamless work through the mesh (IEEE802.11s) networks.
  In this particular case we could investigate possible procedures for conducting MAC and IP level routing.
• Secure Off-load
  Ensuring that network we off-load the traffic to is secure enough. Simulating & Implementing an Authentication, authorizaton, accounting (AAA) server.

Deliverables

• Simulation model in NS2;
• Demo scenario and scripts for seamless handover;
• Demo scenario and scripts on N900 device;
• Papers on 7th, 8th, 9th FRUCT Conferences.

Project team

• Project Leader: Nokilay Amelichev (LETI)
• Developers: Michael Krinkin, Kirill Yudenok

Project homepage is http://osll.spb.ru/projects/show/sw3g

Current project status can be viewed at http://osll.spb.ru/wiki/sw3g.

Our last results in simulation have been presented on the 7th FRUCT Conference ("PMIPv6 based 3GPP/WLAN inter-working MAEMO support challenges") and on AIS/CAD'10 Conference ("Simulation of Proxy Mobile IPv6 in ns-2"). FRUCT8 Paper ("Simulation of 3G/WLAN Offload: First Steps") is pending.