Xin Wang
Bell Laboratories
Mobile Networking Research Department
101 Crawfords Corner Road
Holmdel, New Jersey 07733
Room 4F-502
|
Xin Wang
|
The project is focused on wireless networks where a radio access network replaces point to point links for the interconnection of base stations to radio network controllers (RNC). Using IP to create a radio access network (RAN) will help support anticipated explosive growth of wireless data, merge service and sharing of transport for wireless and wire-line networks, increase scalability, enhance reliability, simplify management and reduce operation cost. The major problem in wireless networks has been how to achieve good utilization of scarce air interface resources. With the introduction of IP RAN, despite its benefits, there is a need for new algorithms for resource control to cope with the strict delay requirements and radio related functionality of IP RAN. The goal of this project is to show that Radio Network Control (RNC) functionality can be implemented in a scalable manner and the IP network is able to support CDMA voice and data efficiently and effectively. We have designed a set of algorithms to effectively control both the load of air interface and backhaul to guarantee the target transmission quality between the mobiles and RNC. In particular, we have proposed and evaluated three congestion control mechanisms to maximize network capacity while maintaining good voice quality: admission control, diversity control, and router control. Using simulations of a large mobile network, we show that the three different control mechanisms can help gracefully manage overload in the IP RAN. This is an on-going work.
GEMS is a family of high speed Ethernet MPLS Switch products designed to deliver Ethernet and IP data services to small, medium and large enterprises and data centers, and provide high-capacity Ethernet aggregation for large xSP and enterprise data centers. GEM Switches will be deployed in conjunction with optical transport (DWDM, SONET/SDH) and IP services products (Core & Edge Routers,IP service switches, VoIP gateways) to enable service providers to deliver IP and Ethernet services at a lower cost-per-port/cost-per-bit than traditional T1, T3, and Frame Relay services that rely on TDM for sub-wavelength grooming, multiplexing and switching of traffic. A network of GEM Switches will provide well-characterized services over Ethernet through packet-level Quality of Service mechanisms tied to the performance needs of individual packet flows. Solutions built around GEM Switches will eliminate the complexity of provisioning transport capacity at multiple layers (IP + ATM + SONET/ SDH) and instead allow service providers to rapidly provision Ethernet services, with sub-lambda bandwidth management capabilities that support a migration to all-optical network for IP services. The challenge of this project is to guarantee the various quality requirements of service providers and enable efficient traffic engineering functions at multiple network layers. The scalability and reliability of the switch at high speed are also crucial. I served as a technical consultant for this project, and provided solutions for QoS support in, and MPLS control of GEMS.
The imminent Content Switch (ICS) is a next-generation intelligent application platform built for distributing and delivering content to a variety of users. ICS moves beyond existing web switching and content delivery products and provides a Layer 2-7 framework for building key content delivery services. It was multi-disciplinary and combined proprietary hardware, firmware, common software, and applications. In this project, I served as a team lead and led the architectural design of QoS subsystem and Packet Tracking and Monitoring (PTM) subsystem for ICS. I designed a complete infrastructure to support QoS for value-added services from Layer 2-7, and designed a Packet Tracking and Monitoring subsystem to support high-speed data tracking, statistics monitoring for service verification, and detailed data records for flexible data and content billing.