For speed: there's 802.11, everything else, Bluetooth

For speed: there's 802.11, everything else, Bluetooth
The biggest challenge in applications development is successful porting to multiple platforms and devices. IEEE 802.11b supports full Ethernet-style data communications. The 802.11b standard does not expressly include support for specific applications. Rather, most applications will be executed through TCP/IP protocols. This approach allows 802.11b-enabled PCs to use existing network applications and resources already on the PC.

The Bluetooth standard supports TCP/IP protocol-based applications much as 802.11b does, and also lists specific requirements for 11 Bluetooth applications. Because products incorporating Bluetooth implementations tend to be lower power, more compact and less expensive than products incorporating 802.11b implementations, they typically require more compact software code implementations. Small handheld, low-power devices have small batteries and limited ROM and RAM (usually in kilobytes, not megabytes). Therefore, the specific applications included in the Bluetooth standard are compact, ready-to-use applications including communications with printers, object exchange (OBEX), and an audio application for headsets. Both the standard applications and the TCP/IP support should enable manufacturers to include Bluetooth without significant additional applications development. Common TCP/IP support should also enable cross-platform software development efforts by third-party suppliers.

Functionality for 802.11b is usually implemented via dedicated servers on wired networks. In corporate applications, users are preconfigured while in the new mobile services planned by companies such as Wayport and Mobilstar (now part of VoiceStream), users go through a registration process. Peer -to -peer communications can be established by selecting another computer as the communications target. Communication between multiple devices goes through a server that distributes files or email to multiple addressed users.

In contrast, the Bluetooth standard provides for smaller ad hoc networks, or wireless personal area networks (WPANs). Connections are created automatically and without assistance from IT/IS departments typically associated with LANs. Bluetooth WPANs can consist of just two units (a master and a slave), or up to eight units (a master and seven active slaves, plus many inactive "parked" slaves), called a piconet. Bluetooth devices may also belong to multiple piconets concurrently.

Users will have a choice for Internet or corporate network connections. IEEE 802.11b will likely be the choice for high-speed access to corporate, home office, and other networks. Bluetooth communications will likely be favored for lower bandwidth communication with small portable devices such as cellular phones and personal digital assistants (PDAs). Wireless access points to connect both types of systems to current hard-wired Ethernet networks are shipping today.

IEEE 802.11b systems are leading the way in wireless networking in such locations as hotels, Starbucks, etc., where users can get high-speed Web and corporate Internet access. Bluetooth communications, even though at lower speeds, will rapidly expand for these applications also, as users seek to network with smaller, handheld devices.

Personal-area networks, or PANs, use Bluetooth wireless connections to replace serial, parallel and other specialized cables connecting PCs to peripherals, keyboards and mice, PDAs and cellular telephones. One Bluetooth unit in a PC can effectively control and interface with up to seven different devices simultaneously.

Wireless peripherals such as keyboards, mice, and accessories to PCs, PDAs, and cellular phones will be a major area of expansion because they're more convenient and they can be used with products that are not big enough to support a cable connector. In most of these devices, Bluetooth technology is the only wireless technology that can meet the stringent, low-power consumption and small size targets.

Bluetooth wireless communications has the added advantage of short latency, real-time voice support for headset and other audio applications. While 802.11b can be used to send digitally encoded voice packets, it has no special support for headset or cordless telephone applications and would require complex DSP processing in the headset. Meanwhile, multiple devices such as headsets, keyboards, mice, and other peripherals can connect simultaneously to a single Bluetooth master unit in the PC. This voice support will be especially useful for early implementations of Voice-over-Internet Protocol (VoIP). Personal digital assistants (PDAs) will predominantly incorporate Bluetooth, but some high-end PDA products will support both. Bluetooth will provide low-power connections to cell phones or new ad hoc networks, while 802.11b systems will provide mobile connections to existing corporate and public networks. Cell phones will likely use only Bluetooth for cable replacement, not 802.11b due to the longer battery life, lower cost, and smaller size.

If laptop users want to have both IEEE 802.11b and Bluetooth communications capability, they will also want to use these protocols at the same time. Because Bluetooth and 802.11b use the same 2.4-GHz frequency band, however, care must be taken when using them together. Although the two technologies can operate simultaneously, concurrent use will result in performance degradation, primarily in the 802.11b communications. Therefore, most first-generation wireless laptops are expected to use these RF protocols separately or in a staggered fashion to avoid interference and its performance impacts.

Coexistence is the next step in integrating both 802.11b and Bluetooth communications in a single system. It refers to the simultaneous 802.11b and Bluetooth communications use in laptops by mid-2002, with the radios coordinating with each other and alternating fast enough for the communications to appear simultaneous to the user.

Actual simultaneous operation will depend on systems being able to adaptively, or intelligently, hop around each other to avoid interference. Adaptive hopping will enable both radios to operate simultaneously while in close proximity to each other by using different parts of the 2.4-GHz frequency band. This technique requires a technical innovation and modest regulatory changes in the United States, both of which look likely in 2002. For users, simultaneous operation will provide a significant advantage. For example, a user will be able to view streaming video over the Internet through an 802.11b connection while using a Bluetooth headset for the sound track.

The combination of 802.11b and Bluetooth communications will replace wires in many current applications. More importantly, it will also cut the cables that restrain developers from producing a myriad of new wireless applications.