Surfing the Web Without Wires

As more and more people use wireless devices to hop on the Web or check their email, there will be an increasing demand for service quality that matches what wireline users receive. At present, those who connect to the Internet with wireless devices often face delays and disconnects.

Part of the problem is that the Internet Protocol (IP) address of a wireless device both identifies the device and specifies which network it can attach to. This makes it necessary to reconfigure the device every time it is removed from the network. To overcome this, a protocol, Mobile IP, allows wireless device users to move from one network to another while maintaining a permanent IP address.

Mobile IP's routing system, however, adds more delay and signaling overhead for real-time services (such as voice over Internet Protocol) that require "fast handoffs" when a user moves frequently from one subnetwork to another. While mobile IP handles mobility from domain to domain efficiently, you need another kind of protocol that will route the packets with minimum latency and overhead between subnetworks within a provider's domain. (And in some wide-area cellular networks, a wireless device must change subnetworks very frequently because topology and frequency limit the areas covered by the subnetworks.)

To help prepare for a future where millions of wireless devices may connect to the Internet via the provider's domain, Telcordia has developed a micromobility protocol for managing the mobility of a wireless device roaming between subnetworks within a domain. Also known as an intradomain mobility management protocol (IDMP), it creates a "mobility agent" that redirects packets (data routed on the Internet) to your device's new point of attachment to the Internet. (A mobility agent is software that uses an algorithm to facilitate Internet traffic forwarding for a wireless device when the device's location is changed to a new location within a domain.

In addition, the protocol's fast-handoff mechanism reduces the duration of service interruption and minimizes the loss of in-flight packets during handoffs between subnetwork base stations. This fits with the requirements for a variety of real-time and other applications in next-generation cellular networks.

For example, there is growing interest in developing an all IP-based network (4G) that promises global roaming across multiple wireless and mobile networks — from cellular networks to a satellite-based network to a high-bandwidth wireless local-area network. The micromobility protocol and its enhancements for fast handoffs (and paging) is intended to prevent the delays and disconnects that would occur in such a network under the current protocol — especially for applications such as voice over Internet Protocol and video conferencing.

The article that Telcordia micromobility protocol developers Subir Das and co-authors Anthony McAuley and Ashutosh Dutta wrote, "IDMP: An Intradomain Mobility Management Protocol for Next-Generation Wireless Networks," appeared in IEEE Wireless Communications.