Introduction

The Networks & Telecommunications Research Group (NTRG) at University of Dublin, Trinity College has pioneered efforts to define what technologies will make up the 4th Generation of mobile systems. We have research efforts on-going in many areas that we see as being important parts of the 4th Generation including: Software Radio, Ad-hoc Networking, self-configuring systems as well as new applications that will use the new networking infrastructure. For further details see the 4th Generation Telephony page.


The 4GPhone Application

Many of our individual researchers develop demonstrators of their work and we encourage them to encapsulate these as layers that will operate in our development testbed. This current software release is intended to demonstrate some of the elements that will make up a 4th Generation Voice Device (mobile phone replacement)

The 4GPhone is a zero-configuration (almost - nodes must currently be supplied with an address) point-to-point voice application designed for operation in ad-hoc networks.

For flexibility the application is built using a layered structure and currently contains the following major components:

4th Generation Phone Stack
  • Other layers, such as encryption, can be added as required.
  • Some details on the layers currently in use:
    Layer Summary Further Details
    Audio Provides a stream of audio packets by capturing from the audio input device. Can operate in both full-duplex (playing and recording simultaneously) and half-duplex modes (transparently switches between recording and playing for hardware that is incapable of simultaneous capture and playback). A variety of compression techniques can be used, providing varying levels of compression that can be changed as required.
    NOM Our zero-configuration name-lookup service inspired by P2P technology, authored by Diego Doval
    SIP Uses a slightly modified version of SIP (Session Initiation Protocol) to provide a signaling mechanism for the establishment of the call. Instead of using SIP servers to provide location it relies on the services of the NOM and DSR layers.
    DSR An implementation of the Dynamic Source Routing (DSR) Ad-Hoc Networking Protocol - implemented by Tim Forde
    Ad-hoc Page
    Broadcast A radio layer that interfaces to an IEEE 802.11b network card using broadcast IP
    Although this is the only bottom layer currently in use, it can be readily replaced with other layers that have been developed to support other underlying network media such as infrared.

    The following screenshot shows the application in action:
    4th Generation Phone Stack

    We have tested this on a Compaq IPAQ H3600 series running Microsoft Pocket PC Vers 2.1 and Version 3 with a Lucent Orinoco Silver PC card for IEEE 802.11b connectivity. It should be compatible with any StrongArm processor running PocketPC 2000 or PocketPC 2002, and using any 802.11 card.

    To download the application please download the following zipped file and follow the installation instructions in the enclosed Readme file. NOTE: This release is copyrighted software and is being made available in BINARY only form for non-commercial research purposes only.
    The ZIP file

    A full-duplex audio driver is recommended. A full-duplex driver for the iPAQ 3600 series can be found on the Compaq iPAQ development site


    Future Work

    This system is extremely adaptable, and will be modified to address other issues currently being examined by various members of the group including:
  • Autoconfiguration of node addresses
  • Global connectivity of the network
  • Security issues