In the project ''Wireless Local Area Network with Integration of
Professional-Quality DECT Telephony'', short WINDECT, wireless LAN and
DECT cordless telephony networks are merged by integrating professional
quality telephony into WLANs. The project is partially funded by the
European Commission (the Sixth Framework Programme "Information Society
Technologies") and by the Swiss Federal Office for Education and Science.
The advancement of digital services over recent years has created a
huge demand for communication systems to meet the "high-speed, high-quality"
requirements. At present, in-house networks still have two parallel
infrastructures: the telephony infrastructure for low-bandwidth but high
Quality-of-Service (QoS) applications like telephony and the computer network
infrastructure for high data-rate but best-effort data traffic. Both networks
consist of a wired infrastructure for fixed access and a wireless infrastructure
for the support of mobility. Both of these network realms are driving the
convergence of different services into a single system. Due to the low bandwidth
of telephony networks, applications such as video conferencing suffer from poor
data rates. The often-used VoIP-approach is likely to have unacceptably large
delay and/or unreliable packet delivery within the required time period.
Acceptable performance is usually obtained in dedicated packet switched
networks offering large and reliably available bandwidth.
The WINDECT approach is to merge the upper layers of the DECT protocol
stack with current WLAN physical layer and MAC layer technology, using a
protocol adaptation layer (PAL); this promises many advantages over VoIP
because the upper layers of DECT are optimized for a voice application.
In the research phase, the project will investigate radio resource
management, power consumption, handover, and quality-of-service (QoS) support
through extensions to the IEEE 802.11a/e WLAN standard. The results will
determine the design of a demonstration system to be manufactured by the
partners in the project.
The project outcome will be DECT-over-WLAN telephones and access points,
which support professional-quality telephony, whereby crucially the quality
of service in the telephony part is not impaired; in addition the compatibility
to existing WLAN data modems is guaranteed. Future devices and applications will
integrate real-time voice/video traffic and packet data.
Strong efforts will be made in order to promote the results of WINDECT
in standardisation bodies and alliances and push the standardisation of
the developed technology. The results obtained in the course of this project
will be of high importance in the design of future wireless communication
networks that combine telephony connections and high-speed data traffic.
Demonstrating and quantifying the advantages achievable in a combination of
WLAN and DECT technology will open up the possibility of impacting future
wireless standards at an early stage.
Main tasks of the Wireless Communications Group (WCG)
in this project are:
- Research on QoS issues, coverage, relaying, (cooperative) MIMO and diversity techniques
- Development and implementation of the Protocol Adaptation Layer
- Integrating and testing/debugging of the telephone terminals
- Leader of the dissemination work-package (among other things the developing and maintaining the WINDECT web site)
"The project reinforces European competitiveness by extending the existing
expertise in wireless networking in the direction of QoS support. The question
of QoS and real-time data transfer in WLANs plays a major role in many envisioned
future applications", explains technical project manager Michael Kuhn from Ascom.
"The goal is to create a superior technology for Telephony over Wireless LAN", says
project coordinator Hans-Peter Bauer from Winfinity.