Hot Topics In The Mobile Computing Industry

MOBILE IP

MOBILE IP is a  term that is misunderstood by many practitioners. In research parlance, Mobile IP is modified IP protocol to address the important characteristic of mobile users - that they move from place to place physically and can not utilize a static IP address assigned to the end of wire. This is to distinguish between a logical IP user and a physical IP user. A new generation of Mobile IP standards (when blessed by IETF taskforce) will address this requirement. According to a paper by Stanford University, Mobile IP is a mechanism for maintaining transparent network connectivity to mobile hosts. Mobile IP protocol enables a mobile host to be addressed by the IP address it uses in its home network (home IP address), regardless of the network to which it is currently physically attached. Therefore, ongoing network connections to a mobile host can be maintained even as the mobile host is moving from one subnet to the other.

Click here on a Stanford University paper.

Click here on another paper - a white paper on the subject.

Click here on a more formal tutorial in the form of a technical paper by Charles Perkins of Sun Corporation (for a more advanced practitioner) on Mobile IP This paper has 46  references - good for those who love Mobile IP and want to get immersed - you product developers and the academic types.

Mobile IP and IPv6 ; Mobile portion of IPv6 does not address full requirements of Mobile IP. 

The term "Mobile IP" is also being used, sometimes (though incorrectly) to indicate emulation of IP interface against a myriad of wireless protocols that have proprietary native access or air protocols designed by wireless network infrastructure vendors, such as Ericsson, Motorola, Nokia, Qualcomm, etc..  Smart IP from Nettech, IBM eBusiness Gateway (ex-ARTour) and Motorola's DataTac 2 private network use spoofing techniques to pretend to the applications that they are connected to an IP network when they are not.  Click here for more information - this article gives only the latter perspective, though - Editor.   The right term here should be wireless IP.

Also click on an introductory article by Peter Savvy - an independent consultant, "Internet to go, Now with Mobile IP"- for the basic user. Go to article by Perkins above for more formal treatment of the subject.

Do not get confused if vendors snow you about Mobile IP. Ask them pointedly what exactly they have and is it compatible to the IETF standard and will it inter-operate with wireline TCP/IP-supported applications.   Readers may correct me by an e-mail, if I am off base here" - Editor.

More Mobile IP Resources on the NET - Click here to get web resources on this subject.

Added in October 2002

Products Implementing Some Sort of MobileIP Concept

• WirelessIP "Anywhere" Broadband  - Allows IPWireless subscribers to roam seamlessly between cell sites at high speeds and to move easily between other networks such as 802.11, UMTS FDD, CDMA2000, or General Packet Radio Service (GPRS) without losing their connection. For example, a user with a laptop connected to a corporate wireless LAN can automatically switch to the wide area IPWireless broadband network without losing the connection.
• Birdstep's WiFi and GSM Roaming software