Hybrid 802.11 (WLAN) - WAN (Cellular) Mobility Solutions

October 1, 2001
by Derek Kerton

In the last newsletter (available on my website) I discussed the emergence of public 802.11b access points, and their potential impact on carriers. The 802.11 (Wi-Fi) access points are springing up in airports, hotels, and coffee shops around the country, installed mainly by a new breed of ISP represented by firms like Mobilestar. They are selling easy-to-use, very fast connections in the same places where one would expect 3G data connections to be popular. There are also numerous grass-roots community efforts giving away the same connectivity for free <http://www.villagevoice.com/issues/0133/meyers.php>.

The advantages of public Wi-Fi access are numerous. The 802.11b standard has quickly matured and the Wi-Fi seal guarantees interoperability among disparate manufacturers. A user who already uses 802.11b in the office or home can very easily connect at any of the wireless LAN hotspots. The Internet connections are typically uncongested and broadband speeds.
In my opinion, the disadvantages do not outweigh the pluses, but they will take some time for the industry to overcome. They are:
- most wireless ISPs work and bill independently, so a paid membership with one WISP will not allow roaming to another. This is like the very early stages of the cellular phone industry.
- It has been difficult to find out where the public Wi-Fi hotspots are located. This problem is starting to be solved by firms like WiFinder, which provides a free online directory including all fee and free hotspots.
- coverage is only in some 1200 known Wi-Fi hotspots, which leaves a whole lot of mother earth without coverage. This means that a mobile worker can take advantage of public Wi-Fi services where available, but will need a WAN (cellular-type) data solution to fill in the abundance of space in between.

Here’s how the first two problems will be overcome: Like the cellular industry, the WISPs will undergo consolidation and strike roaming agreements such that users will not need to subscribe to each one. Directories like WiFinder’s will help users locate the hotspots.The third problem will be slowly overcome by additional hotspots coming on-line, but also by the development of hybrid solutions. A hybrid solution will be one in which a cellular modem connects the user when on the road, in a car, and otherwise mobile, but not at a hotspot. To complete the hybrid, Wi-Fi protocols will be automatically selected and used whenever the user is located in range of an access point. In order for this to be a “hybrid solution” and not just two separate solutions, there should be simplification and consolidation in three areas:
billing
hardware
protocol selection.

Billing: An ideal solution would not increase the number of billing relationships the consumer has. Optimally, your cellular carrier would strike back-office billing relationships with WISPs such that Wi-Fi access fees would appear on your existing cellular bill.
Hardware: Ideally, a user would not need to deal PCMCIA cards like a Vegas pro. A single PCMCIA card could be built with dual mode radios to support both 802.11b and cellular networks (CDPD, GSM, CDMA, or 2.5G). This story deals mostly with laptop computers, but PDAs and other terminals could also be made with dual mode radios built in or as accessories.
Protocol Selection: Optimally, the hybrid system would constantly monitor what networks are available, and choose the best network. This means that while on a train, your card could select a CDPD connection, but once arrived at the train station, an 802.11b network would be automatically detected, and your Internet connection would be automatically transferred to the faster access.

After considering the three points above, it becomes clear that there needs to be a whole lot of cooperation before a hybrid solution becomes reality. Most importantly, it requires carrier involvement. Involvement demands that carriers radically alter their vision of high-speed mobile access from a pure 3G world to one in which WLAN access eats up a big chunk of profitable 3G usage. That’s a hard pill for carriers to swallow after sinking billions into 3G technologies and spectrum. But carriers need to make a choice, and they need to make it quickly before new companies like Mobilestar grow and become incumbents, just like ISPs have for wired access. Cannibalization has never been an easy choice for companies, but the alternative is to let someone else eat your lunch. (be careful here, as ALL today’s WISPs are in trouble - even MSTR is looking for buyers - quietly.)This can be a winning arrangement. Carriers can offer the WLAN community a wider footprint and mobile access and the capital which the small firms lack for network build-out. WLANs can offer carriers the ability to offload traffic from their expensive cellular networks onto more efficient Wi-Fi nets.

My conclusion is this; carriers need to embrace the emerging Wireless LAN phenomenon. They should get involved, get relationships or ownership of WISPs, and limit the damage that they will incur by standing still.

Any company annoyed with being considered a dumb pipe needs to, on occasion, defy that description.

More:
<http://www.mobileinfo.com/News_2001/Issue31/datacomm_PWLAN.tm.htm>
<http://www.mobileinfo.com/News_2001/Issue31/wlan_sage.htm>