Cellular Networks and Technologies

We cover all research areas of cellular networks, from call admission through standards to mobility management. Particularly:

• We are developing protocols to integrate and optimize the processes of the paging and update mechanism. We are extending our LeZi-Update procedure to heterogeneous networks where boundaries of cells of different technologies are likely not to overlap.

• We are interested in service admission control and how admission control may include flows whose service rate is adaptable.

Wireless Mesh Networks

As next generation wireless networks evolve around broadband services, the design of the wireless access network, which accounts for a significant portion of operation costs, is an area of concern. The goal is to replace the vertical architecture of existing wireless backhaul with a horizontal mesh architecture, where the network elements communicate with each other (each acting as a wireless router) instead of communicating with a central controller. The advantages of a mesh network, which has been the underlying topology of the public Internet, are many: including higher coverage, multi-path routing, etc to mention a few. The objective is to interconnect the network elements in a mesh topology, using short, high-speed wireless links between the nodes, which provide carrier-class characteristics without incurring high costs to the operators. In the context of this area we are interested in finding efficient topologies based on Petersen graphs, Fractal concepts, or using optimization methods .

Performance of Wireless Networking Standards

The goal of this activity is to develop a deeper understanding of the performance and impact of different wireless networking standards. Among others we are investigating performance issues in:

• Wi-Fi (IEEE 802.11x) wireless LANs

• Bluetooth (IEEE 802.15.1) wireless PANs

• Wi-Max (IEEE 802.16) wireless MANs

• UWB (IEEE 802.15.3) wireless PANs

• IEEE 802.15.4 and Zigbee wireless PANs

We investigate how the above protocol could be enablers of ad hoc (including sensor) and cellular technologies.

Ad Hoc Networks (MANETs)

Our investigations of Ad Hoc networks cover the entire spectrum, from providing congestion control of varying link usages through connecting MANETs to the Internet  to routing and MAC issues .

Next Generation Wireless Networks – System Integration

This activity deals with defining a way for a user the perceive all access networks as if it were a single access network. To this end, we are investigating active networks and mobile software entities to provide with the proactivity needed. We are in the process of establishing a simulation and testbed of a network integrating Wi-Fi, GPRS, and Bluetooth access technologies and thus enabling seamless vertical handoffs between them.