04-07-2012, 11:02 AM
CAN MOBILE IP BE USED AS A LINK BETWEEN IMT 2000 TECHNOLOGIES AND OPERATORS
MOBILE IP BE USED AS A LINK BETWEEN.doc (Size: 128.5 KB / Downloads: 76)
ABSTRACT
IMT 2000 technologies provide IP based services to cellular telephones. Network operators are consequently offering data services comparable to Internet Service Providers. A rising issue is to provide interoperability between the technologies and between the different providers. A possible candidate suggested by 3GPP and 3 GPP2 is Mobile IP.
The major decision point whether or not Mobile IP is suitable is the performance of handoffs between different networks. The paper therefore studies the performance delay for TCP, UDP and suggests an enhanced Mobile Internet Protocol since MIP proved to be unsuitable. IIP is using strong cell switching and avoids tunnelling. It therefore performs superior to Mobile IP. While Mobile IP performs handoffs with an end-to-end delay for TCP within seconds and UDP traffic in average in about 500ms IIP allows handoff to be performed below 100 ms.
INTRODUCTION
The first IMT 2000 standards are emerging and the first UMTS licenses are auctioned in the UK. In about two years the mobile user will face a variety of providers offering services based on analogue wireless systems, GSM (900 and 1800) and UMTS. The providers are facing increasing competition and consequently will steadily offer more services such as data services beyond a diversity of plain telephony and messaging services.
Schulzrinne et al. [1] shows a scenario on how future telephony integrates with data services using the Internet. Telephony on packet-based networks may offer services such as dialling to different telephones of one user in a multicast way.
MOBILE IP
In 1996 Mobile IP was proposed [2] as an enhancement of IP to provide support for mobility in contrary to portability. Portability requirements are provided with DHCP [3], which allows setting of new parameters within a network segment during the booting process of a host. Mobility tries to avoid the reconfiguration of a host while moving between different networks. Mobile IP requires new network elements and specifies a protocol for the interaction of the new components and the host. Very briefly the new components and notions are Mobile Node, Correspondent Node, Home Agent, Foreign Agent. As depicted in Figure 1 the Mobile Station (Mobile Node) moves between two operators with different IP networks.
MOBILE IP USING STRONG CELL SWITCHING MOVEMENT DETECTION
One optimisation is to study the influence of the movement detection method and to identify the possible gain if strong cell switching were used. An experiment therefore has been set up to explore the influence of the different type of movement detection method. In addition the experiment should provide UDP measurements on Mobile IP since UDP is important for IP telephony. Figure 4 shows the measured result.
ITINERANT INTERNET PROTOCOL
IIP is an enhanced version of Mobile IP optimised for Wireless Networks using Home Location Registries (HLR) and Strong Cell Switching movement detection method. The design is based on the suggestion of Jain [6]. The protocol uses as entities Mobile Nodes, Home Location Registries and Correspondent Nodes. It assumes that all Nodes are mobility enabled, i.e. all nodes have an IIP compliant mobility protocol stack. The functionality described in brief: A Correspondent Node first queries the Home Location Registry and obtains the IP address of the Mobile Node at its current location. Further traffic is directly addressed to the Mobile Node. The Mobile Node informs the communication partner and the Home Location register whenever it moves between networks. Movement is detected via a beacon provided by the data link layer of the used transport technology. Figure 5 depicts the protocol timeline [8].