Backers of Bluetooth are now tackling tasks that were not on the agenda when the system was devised. A host of new problems must now be solved, says Bill Pechey
After the recent Bluetooth Congress, I've been musing on what the future holds for Bluetooth wireless connectivity, and how it will differ from the original plans for the technology. Initially, Bluetooth was conceived as a replacement for cables connecting hardware such as mobile phones, PDAs, headsets and printers via low-power low-cost radio links.
Such connectivity, often called the personal area network (PAN), is certainly the first area to see Bluetooth products appear in volume. It should soon be common for users to keep their mobiles in their pockets or non-metallic briefcases, whilst retaining connections to a PDA and a headset, linking all the devices through Bluetooth.
This arrangement allows users to manage calls using a PDA screen and keeping the mobile phone away from the body can improve radio performance and reduce health risks. The phone/PDA combination, linked by Bluetooth, is also great for email and WAP, especially over GPRS networks.
Many firms are extending beyond the PAN to manufacture equipment that will connect Bluetooth devices to other networks. There are already Bluetooth access points for ISDN, ADSL, Ethernet and the ordinary telephone network. Most commonly these Bluetooth links provide connections to Ethernet LANs. Bluetooth links will be popular in corporate offices where they can provide PDA access to email, WAP, voice, etc just like connecting through your mobile, but much faster.
However, Bluetooth was not designed to go beyond simple point-to-point connections and was not intended to provide true wireless LAN functionality. This problem is being addressed by the Bluetooth SIG, which is close to completing the Bluetooth Network Encapsulation Protocol (BNEP), which will be able to carry any form of LAN traffic. This should enable a notebook PC to use Bluetooth to connect to a LAN and operate just as if it were wired, apart from the slower speed, of course. BNEP also allows any software written for LAN operation to be used, without modification, over a Bluetooth link.
BNEP does not solve every problem, however. Bluetooth users will want to move around the office, while keeping voice or data connections. Bluetooth has no special mechanism for handing over the connection from one access point to the next, and there could be an interruption of a few seconds each time it happens. This may not matter for data connections, but it's disastrous for voice. Again, the Bluetooth SIG is trying to solve the problem, but it's difficult to see how it can be done without making existing radio chips incompatible.
Some networks made up of these Bluetooth access points will be in public areas such as airports and railway stations. The operators of such systems will want to be able to locate users pretty accurately so they can offer directions or precision advertising. Some proprietary location mechanisms are appearing, but no standard scheme has emerged yet. There are privacy issues here as well do you want the airport owner to know that you paused for a while next to the soft-porn magazines?
These enhancements to Bluetooth will come slowly, but should be complete by the time Bluetooth phones and PDAs are available in volume. Only time will tell whether the wireless LAN capabilities of Bluetooth will be important, but I'm pretty sure that, once there are enough devices around, public information services with advertising will pop up everywhere.