Seamless mobility: The ultimate destination

Jun 27, 2003 12:00 PM, By Goli Ameri

Seamless mobility makes sense to consumers. It gives them ability to do their business wirelessly anytime anywhere without giving much thought to the background technology or maintaining a connection. Users will find their own usage models for wireless networks and will not necessarily use the networks for their originally intended purpose. In Europe, for example, Bluetooth was included in mobile phones to allow hands-free usage due to legislation regarding the usage of mobile phones while driving. Bluetooth-enabled cell phones, however, are used today by many business people to connect their laptops to GPRS networks. Seamless mobility bridges the different wireless markets of "mobility" and "portability."

Seamless mobility allows subscribers to have the best and most appropriate network connection at all times regardless of location and it allows network operators to share in all types of wireless revenues. With current spectrum allocation scenarios around the world, the tradeoff has always been speed vs. coverage, and hence the wireless network of the future will be a hybrid of 2G, 2.5G, 3G, Wi-Fi, Bluetooth and UWB technologies with roaming/billing systems that provide the bridge (see Table 1). The day is just around the corner where there will be contiguous Wi-Fi coverage in dense metro areas and 2.5G or 3G in more outlying areas. Service providers will derive their revenues through guaranteed service levels and content.

The trend toward seamless mobility is evident in vendors' product plans. Qualcomm is currently evaluating and developing Wi-Fi features on CDMA phones. There are rumors that Motorola might announce a 2G/2.5G/3G handset with Wi-Fi capability called Paragon 2. Mobility Network Systems has integrated its WiFiRAN (Wi-Fi Radio Active Network) into Rogers AT&T Wireless' GPRS network in Canada to provide seamless coverage. T-Mobile is developing software with Boingo to allow users to manage their connections between the company's GPRS and 802.11 service and seamlessly move from one to another.

Some service providers and vendors have already trialed the concept of seamless mobility. In early 2001, Ericsson and Telenor trialed handoffs between UMTS and HiperLAN2. Just recently KDDI R&D Labs of Japan and Cisco tested seamless data communications between 3G and WLANs by using a new router from Cisco allowing car travelers to switch between networks depending on their location. The company is also experimenting with high-speed WLANs that can deliver HDTV transmissions to PDAs. University of California San Diego is trialing WLAN/WWAN roaming with Qualcomm in San Diego through a roaming WLAN-enabled bus that communicates with Qualcomm's trial CDMA 1X-EV system. There has also been some speculation in Australia regarding the establishment of seamless roaming between Arraycomm's iBurst 1 Mb/s service and WLANs.

There are already technologies that simulate the concept of seamless mobility. IPWireless provides seamless high-speed wireless access while at work, at home or on the road operating in three licensed bands in addition to the unlicensed 802.11b. Flarion's flash-OFDM technology and infrastructure is positioned as an alternative to 3G with the ability to hand off connections to 802.11-based wireless LANs. Arraycomm's i-BURST technology offers 1M bit/sec speeds to all users of its WWAN service (when constructed).

Lucent Technologies along with HP, iPass, ipUnplugged, Proxim and Sierra Wireless and others will be delivering a 3G/802.11 integration application, which is based on technology developed by Lucent's Bell Laboratories to allow enterprise users to switch networks between CDMA2000/W-CDMA and 802.11 networks. Although these types of applications are currently for vertical industries and have not yet been fully commercialized, before long they will become mainstream as more PDA users become prevalent. In March 2003, Texas Instruments unveiled a new chipset and concept design for a PDA that can communicate through the three networking technologies of GSM/GPRS, Wi-Fi and Bluetooth.

Of course, there is no doubt that technological solutions to authentication, billing, and QoS management must be provided before seamless roaming can become a commercial reality. More information on these requirements can be found in eTinium's recently-released study Seamless Mobility: The Marriage of 3G and Wi-Fi.  The trend of the near future however is towards seamless mobility and all wireless carriers should be on board this trend.

Goli Ameri is the President of eTinium Inc., a telecom consulting and market research company specializing in wireless and switching technologies. She can be reached at gameri@etinium.net.