Sandra R. Thuel

IP-based access network infrastructure for next-generation wireless data networks

Next-generation wireless network standards are currently being defined. The access network architectures have several specialized components tailored for their respective wireless link technologies, even though the services provided by these different wireless networks are fairly similar. We propose a homogeneous IP-based network as a common access network for the different wireless technologies. The IP-based access network uses the Internet standard, Mobile IP, to support macro-mobility of mobile hosts, and HAWAII to support micro-mobility and paging functionality of current wireless networks. We also illustrate how the proposed IP-based solution can interwork with existing infrastructure so that deployment can be incremental.

A case for mobility support with temporary home agents

The Mobile IP standard for mobility management on the Internet enables transparent communication between mobile hosts (MHs) and their correspondent hosts (CHs). However, it suffers from triangular routing and prolonged handoff latency problems. Solutions such as route optimization and micro-mobility protocols either solve these problems partially or require costly modifications to the CHs. In this paper, we propose to use temporary home agent (TA) to address both problems without requiring any special support on CHs. TA exploits the locality of user movement observed in recent studies for PCS and wireless data networks. It does so by dynamically selecting a Mobile IP home agent based on the location of the user. The TA allocates a temporary home address, THAddr to the MH, which the MH may use as its source address. The underlying objective is to shorten the distance between a MH and its home agent, which is a critical factor in reducing handoff latency and improving routing efficiency. Our scheme is shown to outperform Mobile IP and is comparable to route optimization (RO) through both quantitative analysis and ns simulations. While our approach focus on improving the performance for sessions that are initiated by the MH, methods for optimizing traffic handling for sessions initiated by CHs are discussed.

Dynamic Configuration of Mobile Devices for Wireless Internet Access

The dynamic configuration of devices plays a pivotal role in supporting plug-and-play operation in IP networks. For devices that are not mobile, dynamic configuration is typically supported by the widespread Dynamic Host Configuration Protocol (DHCP) [5], which replaces burdensome manual configuration procedures and enables the address space to be managed efficiently. The configuration state allocated to devices by DHCP includes the device’s IP address and a series of DHCP options [7] such as routing parameters (e.g., a subnet mask and default gateway), identity information (e.g., the device’s domain name) or service related parameters (e.g., server addresses for DNS, IMAP, HTTP proxy, NTP, etc.). However, since DHCP was designed to serve the configuration needs of trusted clients in a local LAN, it does not support the configuration of devices connected to a remote network, a situation that arises when the devices are mobile.