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Computer Networking: Bluetooth By far, the most common method of connecting computer peripherals is to use cables, although some devices such as keyboards, mouses and mobile phones use infrared (IrDA) technolo­gy. Bluetooth is about to change all that and it’s got nothing to do with dentistry. By GREG SWAIN A LTHOUGH IT MAY sound mysterious, “Bluetooth” is actually the name for a (relatively) new technology that allows PCs, computer peripherals and other devices to be connected using wireless communications. Basically, it’s a short-range radio link that’s designed to eliminate all those messy cables that are now used to connect keyboards, mouses, printers, modems and the like. Bluetooth is also intended to render IrDA (infrared commu­nication) obsolete. The problem with IrDA is that it is line-of-sight only, its range is strictly limited and communication can only take place between two devices at any one time. Bluetooth overcomes all these problems and, once set up, is easier to use as well. In fact, ease of use is touted as one of the big advantages of Bluetooth. The devices automatically find each other (eg, when you bring a laptop in range of a desktop PC), after which the user can carry out a range of tasks, including dial-up network­ing, faxing, network access, file transfers and information exchange. Technically, Bluetooth operates in the unlicensed 2.4GHz band and uses frequency-hopping spread-spectrum techniques. This not only helps ensure security (other security measures are built in) but also protects the system from interference. And because RF transmissions are used, communication between two machines is not just limited to line-of-sight. The actual range depends on the class of the Bluetooth device. Class The BT007 Bluetake USB Dongles (MicroGram Cat. 11904-7) are basically small radio transceivers which plug directly into USB ports. They are Class 1 devices with a range of about 100 metres. 84  Silicon Chip www.siliconchip.com.au 1 devices have a range of about 100 metres in free space, while Class 2 devices have a range of just 10 metres. That latter figure might not sound like much but it’s usually more than enough if the devices are in the same or adjacent rooms. So how do you get two devices “talking” to each other using Bluetooth? Many devices now come with Blue­tooth already built in (eg, mobile phones, printers and stand-alone modems) but in the case of PCs, the answer is to use Bluetooth “USB dongles” or “USB adapters”. As the names imply, these are compact radio transceiver modules which directly plug into the USB port of a PC. What’s available Typical of the gear that’s now available is the BT007 “Bluetake USB Dongle”, as sold by MicroGram Computers (Cat. 11904-7). This is referred to by MicroGram as a “Bluetooth USB Home LAN – Dual Dongle” and is just the shot for a home network without cables – eg, for connecting a laptop to a desktop PC for file transfer or Internet access. The package includes two Blue­ tooth dongles – one for each machine – along with a setup CD and a user guide. Also included are four Velcro sticky pads so that you can secure the dongle to the top of your PC or in some other convenient location. For maximum range, it’s best to position the dongles so that they aren’t shielded by metalwork. The dongles in the BT007 package are Class 1 Bluetooth devices (ie, they have a range of about 100 metres) and the maximum data rate is specified as 1Mb/s. This data rate is much slower than for a conventional 10/100Mb/s wired network (Ethernet) but is still adequate for exchanging data in most situa­tions, provided you’re not often moving very large files. The supplied setup software comes on a CD and is compatible with the Win98SE, WinMe, Windows 2000 and Windows XP operating systems (note: neither Windows 98 nor Windows NT support USB). Also on the CD is a free copy of Symantec’s WinFax Pro 10.0 plus a trial version of WinRoute Lite which is necessary for internet access under Win98SE/Me. By contrast, Windows 2000/XP rely on Internet www.siliconchip.com.au Fig.1: “My Bluetooth Places” lists the various services that are available and works a bit like the familiar “My Network Places”. Fig.2: the “Bluetooth Configuration” dialog is accessed via the icon that’s placed in the System Tray. Most of the options are self-explanatory. Connection Sharing (ICS) for this function (it doesn’t work with ICS under Win98SE/Me). Getting it up and running is basically a matter of first installing the application software on each machine, then plug­ ging in the dongles into the USB ports. The dongles are then automatically detected and the drivers installed. This also places a new icon in the System tray, along with a shortcut to “My Bluetooth Places” on the desktop. For network access, one machine must be set up to act as a server. As mentioned above, this involves enabling ICS on a Windows 2000/XP machine or installing Win­Route Lite on a Win98SE/Me machine (this is all described in the User Guide). The other machines then act as clients. And that’s it – your system is now Bluetooth-enabled! Double clicking the new icon in the System Tray brings up the “Bluetooth Configuration” dialog as shown in Fig.2. You can perform a variety of tasks here, including setting the The Poke 2th Blue­tooth CF Card (MicroGram Cat.11902-7) is a compact flash (CF) card designed for devices running Windows CE. This is Class 2 device with a 10-metre range. September 2002  85 Bluetooth: continued Not much bigger than your thumb, the “Poke 2th” Bluetooth USB Adapter” (Micro­ Gram Cat. 11901-7) also plugs directly into a USB port. This is another Class 2 device (ie, it has a 10-metre range). manager data such as business cards, email messages and notes. • Information Synchronisation: this allows two Bluetooth-enabled devices to synchronise Personal Information Manager data. • Network Access: this establishes a wireless connection between the client and a server that’s physically connected to a Local Area Network (LAN). If the client has permission from the server, the wireless connection can be used as if the client were hardwired to the LAN. What else is available? security level, specifying default folders for information exchange, and setting up “pairing” and accessibility. Pairing allows devices to be set up so that you don’t have enter access information each time a connection is attempted. My Bluetooth Places The “My Bluetooth Places” window dialog works a bit like “My Network Places” on the Windows desktop. It also allows you to enable and disable the various services that are available (see Fig.1). These services include the following: • Bluetooth Serial Port: establishes a Bluetooth wireless connection between two devices. The connection may be used by an application as though a physical serial cable connected the devices. • Dial-Up Networking: a Bluetooth client can connect to the Internet via a modem that is physically connected to the Blue­tooth server. • Fax: a Bluetooth client can send a fax via a fax machine that is physically connected to the Bluetooth server. • File Transfer: when the File Transfer service is estab­lished between two Bluetooth devices, you can easily browse, drag/drop, open, print, cut, copy, paste, delete or rename files and folders in local and remote directories. • Information Exchange: this service allows two Bluetooth-enabled devices to exchange personal information Price and availability Why Bluetooth? Now for the $64,000 question: why is it called “Bluetooth”? The term comes from Harald Blatand who was a Danish Viking king during the tenth century. Blatand translates into Bluetooth in English and his big claim to fame was that he managed to unite Denmark and part of Norway into a single kingdom – just as Blue­tooth is now uniting PC equipment. Apparently, Harald wasn’t the pillaging type of Viking legend. Instead, he introduced Christianity into Denmark but that didn’t stop him from coming to a sticky end – he was killed in 986 AD during a battle with his son, 86  Silicon Chip Also available from MicroGram is the “Poke 2th” Bluetooth USB Adapt­ er” (Cat. 11901-7). It’s not much bigger than your thumb, plugs directly into the USB port and is a Class 2 device (ie, it has a 10-metre range). Apart from the smaller range, it works exactly the same as the BT007 dongle described above – even the software is the same. It is ideal for transferring data between your notebook/PC and a Bluetooth-enabled PDA or mobile phone. In a similar vein, MicroGram also has the Poke 2th Blue­tooth CF Card (Cat.11902-7) – a compact flash (CF) card designed for devices running Windows CE. This is another Class 2 device (10-metre range) and comes with its own application software (on CD ROM) and a comprehensive User Guide. who then succeeded him as king! The choice of the term “Bluetooth” also reflects the influence of companies in the Baltic region in telecommunications. In fact, the basic technology was originally developed by Ericsson Communications. Finally, the $1,000,000 question. Did Vikings really wear those funny helmets with horns stuck on them? Well, according to numerous websites, they did wear metal helmets to deflect blows to the head during battle but there were no horns on these hel­ mets. It’s all the stuff of myth. The following equipment is currently available from Micro­Gram Computers (all prices include GST): (1) Bluetake USB Dongle, BT007 (includes two dongles); Cat. 119047 – $349.00. (2) Bluetake USB Dongle, BT007 (single dongle); Cat 11903-7 –$199.00. (3) Bluetake 2th USB Adapter, BT009S (single adapter); Cat 119017 – $149.00. (4) Bluetake 2th CF Card Type 2, BT100S (single card); Cat 119020-7 – $199.00. For further information, contact MicroGram Computers, Unit 1, 14 Bon Mace Close, Berkeley Vale, NSW 2261. Phone: (02) 4389 8444. Their email address is sales<at>mgram.com.au or go to www.mgram.com.au SC www.siliconchip.com.au