MIH 802.21 standard: Current Progress and Future Outlook

Current Progress and Future Outlook
The MIH 802.21 standard is still a work in progress. With the newly elected chair as of May 2005, Vivek Gupta, the working group hopes to make progress at a faster rate. The team is actively communicating with one another via email (email archives can be found here: http://www.ieee802.org/21/email21/) and scheduled meetings. The next coming teleconference meeting for the team is April 20, 2006. The following subsections describe the milestones achieved and expectations for the 802.21 standard.

Accomplished Milestones
The milestones accomplished [1] are listed with the least recently achievement on top and ending with the most recent.
2003 — IEEE working group chair people discuss need for standard support “media-independent handover services.”
March 2004 — 802.21 working group launches to address potential standards for MIHS.
September 2004 — Call for proposals for the new standard. Initial work items defined.
November 2004 — Proposals received by 802.21 group. Submissions closed.
January 2005 — Debate and discussion regarding submitted proposals and how to reach compromise.
May 2005 — 802.21 working group complete first draft for standard.
Shortly after finalizing the documentation for design of the 802.21 standard, implementation will begin. The working group will then work closely with companies to get the 802.21 standard established.
5.2 Expectations and Future Outlook
Standards take from 1-3 years to complete. It may take up to 3 years for the 802.21 standard to be complete, but the “typical time frame for IEEE standards more complex than 802.21” is three years [2].
The expectations for this standard, listed below, are quoted from Wikipedia [7]:
• Allow roaming between 802.11 networks and 3g cellular networks.
• Allow users to engage in ad hoc teleconferencing.
• Apply to both wired and wireless networks.
• Allow for use by multiple vendors and users.
• Compatibility and conformance with other IEEE 802 standards.
• Include definitions for managed objects that are compatible with management standards like SNMP.
• Although security algorithms and security protocols will not be defined in the standard authentication, authorization, and network detection and selection will be supported by the protocol.
As with all other projects, it takes time and effort to design and implement a complete, accurate and well-thought system. Many companies are keeping an eye on 802.21 because they want to be able to implement this technology within their existing client devices. It would of no surprise when 802.21 becomes a standard acquired by every company and end user.

Similar Technology
Unlicensed Mobile Access (UMA) is a similar technology of Media Independent Handover (IEEE 802.21). Basically, UMA is a private version of 802.21. It has the same concept of 802.21, which is to provide roaming and handover services between same and different types of network through different handover mechanisms.

UMA (Unlicensed Mobile Access) Overview
UMA technology allows users to access to GSM and GPRS mobile services over unlicensed spectrum technologies such as 802.11 and Bluetooth. With providers who have deployed UMA technology, subscribers can smoothly roam and handover between cellular networks and public and private unlicensed wireless network using dual-mode mobile handsets. As subscribers transition between networks, they can still experience a consistent mobile service of voice, data and and IMS/SIP (IP Multimedia Subsystem/Session Initiation Protocol) applications through their handsets.
A number of leading companies within wireless industry have joined the developing open specifications of UMA. They are actively working with 3GPP standard organization to develop and maintain these specifications and use them as a formal standard of development. These specifications are open to vendors and carriers of wireless communications systems and applications to develop and deploy UMA related solutions.
All these help to promote the widespread of UMA technology. The following is a list of companies which are participating in UMA development.
Alcatel
British Telecom
Cingular
Ericsson
Kineto Wireless

Motorola
Nokia
Nortel Network
O2
Research In Motion

Rogers Wireless
Siemens
Sony Ericsson
T-Mobile US

How UMA Works
UMA technology works as follows on a mobile subscriber: When a subscriber goes within range of an unlicensed wireless network, his/her UMA-enabled dual-mode handset will check whether the network allows it to connect. If it does, the handset will contact the UMA Network Controller (UNC) over the broadband IP access network to be authorized to access the mobile voice and data services via that network. If the access is approved, all mobile voice and data services would be routed to the handset via that unlicensed wireless network instead of the cellular radio access network (RAN) and the current location of the subscriber will be updated. When the subscriber moves out of range of that unlicensed wireless network, the UNC and handset facilitate will roam back to the cellular radio access network and all the voice and data services will be via the cellular network again. The transitions between networks are totally transparent to the subscriber.

UMA Technology Highlights and Architecture
Highlights of UMA Technology [8]:
• To deliver smooth and consistent voice and data services over unlicensed wireless networks.
• To provides the same identity for mobile services over unlicensed wireless networks and cellular radio access networks.
• To transit (roam and handover) smoothly between unlicensed wireless networks and radio access networks.
• To be independent of underlying unlicensed wireless network type (e.g. 802.11, Bluetooth)
• To use the same security as current GSM mobile networks.
• Capable to operations of cellular radio access networks.
• Transparent to current existing network device (e.g. router, access point, modem)
• To utilize standard broadband IP access networks (e.g. DSL, Cable. T1/E1, Broadband wireless, FTTH, …)
• To ensure the low cost of existing or future mobile core network infrastructure.

Architecture of UMA Technology
Advantage and Disadvantage of UMA technology
Advantages [9]:
• Allows providers or carriers to increase coverage using low cost Wifi access point instead of expensive base stations.
• Subscribers have perfect coverage at home.
• Subscribers can have once single number for both home and cellular phone services.
• Subscribers have only one bill for both internet and cell phone plans.
Disadvantages [9]:
• It is hard to determine the current geographic location of a handset over the internet. As a result, a subscriber in U.S. might buy a UMA handset and give it to his relatives in England so they can enjoy cheap calls.
• Battery life is quite limited because handsets must have two radios on board and both radio must keep scanning for networks all the time.
6.3 Comparison of UMA and 802.21
Since UMA and 802.21 are similar technologies, at some level, we should be able to predict the future outlook of 802.21 based on the current progress of UMA. Some companies already have products of UMA technology. One of the goals of UMA is that every subscriber could have only one number for both home and cellular services. Therefore, we can assume that for 802.21, we may be able to use one account to access the ADSL/Cable internet services at home and Wifi/Hot Spot wireless internet services outdoor. Moreover, we may have only one bill for cable TV, cellular phone and internet services in near future since 802.21 provides handover between wired and wireless network. Can you imagine that one day, while we are having a video conference, we can just unplug our laptop from our home network, go out to our cars, to the airport and still have the video conference going on?
7.0 Conclusion
Media Independent Handover simplifies our life with networks. After studying MIH in a certain depth, we can see that it is a really powerful tool that can connect all the different networks together to act like one. Nowadays, network is already a part of our daily life. Cellular phones, Internet, e-mail, instant messages, etc, are all related to networks. MIH breaks the walls between networks and let us take a shortcut without going on the old, long and winding way. That definitely simplifies things a lot, and that is what technology should be.