Browse Prior Art Database

MiP for a Multimode Terminal

IP.com Disclosure Number: IPCOM000130970D
Original Publication Date: 2005-Dec-10
Included in the Prior Art Database: 2005-Dec-10
Document File: 3 page(s) / 40K

Publishing Venue

Siemens

Related People

Juergen Carstens: CONTACT

Abstract

Mobile IP (Internet Protocol) enables devices (e.g. mobile terminal) with a single interface to jump between networks while maintaining ongoing communication sessions. The problem is that Mobile IP will no longer behave efficiently, if this device has more than one interface. Its design forces all sessions communicating over one interface to hand over together, as the mobile terminal moves. The proposed solution introduces a new method to enhance current Mobile IP enabled devices to support operation on a multi-homed device where different applications wish to use different device interfaces. In the following, the basic operation of Mobile IP will be described, to give a better understanding of the technical problem. Mobile IP was developed to allow traffic to be forwarded to the device regardless of the point of attachment to the network. This is possible by tunneling all traffic destined for a mobile device to a "care-of-address" (CoA) that represents the current device location. While moving the terminal changes CoAs and traffic is redirected to the new point of attachment. A schematic design of this solution is shown in Figure 1. It includes the following details: - the device has a permanent home address (HoA) that is used by correspondent nodes as a destination address - furthermore it has a CoA that represents its current point of attachment - a device called "home agent" is located within the users home network and holds a mapping between the device's home address and its current location - information packets which are addressed to the home address are intercepted by the home agent, tunneled to the CoA and therefore the device at its current location - the device updates the home agent with new CoAs while it is moving

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MiP for a Multimode Terminal

Idea: PhD Robert Hancock, UK-Romsey; Eleanor Hepworth, UK-Romsey; Alessandra Pandolfi, DE-

Muenchen

Mobile IP (Internet Protocol) enables devices (e.g. mobile terminal) with a single interface to jump between networks while maintaining ongoing communication sessions. The problem is that Mobile IP will no longer behave efficiently, if this device has more than one interface. Its design forces all sessions communicating over one interface to hand over together, as the mobile terminal moves. The proposed solution introduces a new method to enhance current Mobile IP enabled devices to support operation on a multi-homed device where different applications wish to use different device interfaces.

In the following, the basic operation of Mobile IP will be described, to give a better understanding of the technical problem. Mobile IP was developed to allow traffic to be forwarded to the device regardless of the point of attachment to the network. This is possible by tunneling all traffic destined for a mobile device to a "care-of-address" (CoA) that represents the current device location. While moving the terminal changes CoAs and traffic is redirected to the new point of attachment. A schematic design of this solution is shown in Figure 1. It includes the following details:

- the device has a permanent home address (HoA) that is used by correspondent nodes as a destination address

- furthermore it has a CoA that represents its current point of attachment

- a device called "home agent" is located within the users home network and holds a mapping between the device's home address and its current location

- information packets which are addressed to the home address are intercepted by the home agent, tunneled to the CoA and therefore the device at its current location

- the device updates the home agent with new CoAs while it is moving

For this kind of Mobile IP the traffic destined for a mobile device is tunneled to a single CoA and all active sessions are handed over as one when the device changes the point of attachment. This solution is sufficient for single homed devices (i.e. a device with only a single point-of-attachment to the network). However, devices with multiple interfaces are not able to use alternative routes (or different home agents) for different applications while being controlled by a basic Mobile IP with constraints to force all application traffic to follow the same route across the network.

The previous solution which allows applications to run across several interfaces (i.e. using multiple points of attachment) is schematically reflected in Figure 2. It is an extension to the Mobile IP which enhances the home agent to support multiple CoA with a single home address. Therewith, filters are added to the home agent and configured by the device to control to which point of attachment the application data should be tunneled. These filters can be based on different policies. The problem of th...