Another article written for Australian Net Guide, more looking back at the crystal ball…

As Internet access devices become smaller and more mobile, savvy net users are breaking the wired shackles that have traditionally bound them to a wall socket. Increasingly, tiny, powerful machines such as Toshiba’s Libretto and the 3Com PalmPilot, are pushing the envelope on where people are surfing the net, and wireless networks are following to deliver the connectivity this new breed of devices require. Below are ten frequently asked questions to deliver a grounding in the latest in wireless communications.

1) So what are the wireless options?

The most familiar wireless connection in Australia uses the GSM mobile phone network to transmit data in digital packets. The GSM system has several limitations, most notably high cost and poor data throughput rates. The GSM network was designed to transmit voice, so the CODEC, the digitisation and compression routines used to maximise the number of calls that can be jammed into a given slot of spectrum, has been optimised for speech. This speech optimisation expects data (in this case sounds) to occur with frequents pauses, and the compression routines use these pauses to pack additional infomation into a spectrum slot (in this case, other peoples calls). Typically, when binary data in the form of a file transfer or similar is transmitted, the underlying communications protocols, such as FTP or HTTP regulate the data to transmit in a steady stream, to maximise the network connection. This style of protocol does not work efficiently with the GSM protocols, limiting data speeds to 9600bps to 14.4kbps, significantly slower than the 33.6kbps or 56kbps typically delivered by standard phone lines.

2) What about analogue phones?

The limited call quality of the analogue network is adequate for voice transmissions, but cannot support viable connection sppeds for data communications.

3) What else is available?

In the US, telecommunications companies are trialling a newer standard called CDMA (Code Division Multiple Access). This standard, amongst other advantages, offers the potential to increase data speeds, but is still a system designed primarily for voice.

Competition to the incumbent telcos is also encroaching from the paging companies. Using a new technology, called FLEX, allows two-way paging. Currently, the standard pager network uses a broadcast approach to transmitting messages. This means that a pager message for your doctor on the golf course is sent by every transmission cell in the city. The doctors pager recognises the message is addressed to itself, so it stores the message and beeps. Everybody else in the city with a pager also recieves the message, but their pagers ignore it as it addressed to the doctor. This system wastes vast amounts of spectrum broadcasting messages from every tranmitter in the city. By embedding a tiny transmitter in FLEX pagers, the network can keep track of the location of each device, ensuring messages are only sent from the closest transmitter, and offering the chance to return a confirmation code that the message has been recieved.

By extending this concept, two way paging is possible, and Motorola have launched pagers in the USA that offer tiny keyboards and the ability to send and recieve Email.

The other major challenger to more traditional wireless access methods is from the Ricochet modem. This device, currently only available in San Francico, uses a cheap, low power system of transcievers located atop power poles. Each transceiver uses a central wired access point, which consists of a similar transciever terminating to a high bandwidth digital link such as a T1.

Users buy or lease a radio modem that velcros to their laptop or PDA and pay a monthly access fee for approximately 28.8kbps data throughput. The lightweight, battery operated devices allow users to surf the web and access Email from anywhere within the coverage area.

4) What do you need?

To gain wireless access now in Australia, GSM is the only realistic option. Depending on your access device, either a notebook or a PDA, you will need a cellular compatible modem and a mobile phone or a cellphone with in built modem emulation and the approprate software.

5) What’s the best solution for a laptop?

Each digital phone maker has proprietary devices to connect a laptop. Nokia currently ships several phones which include modem emulation and through the use af a special cable, and the included software, plug straight in to the notebook serial port. Ericsson will have a similar offering shortly, but currently ship PCMCIA modem cards that connect directly to their phones.

6) What about for a PDA?

Both the Windows CE devices, and the 3Com PalmPilot offer mobile solutions. Both devices have inbuilt TCP/IP drivers to allow web browsing and Email access. While the greyscale displays of the current generation of devices are unlikely to challege a traditional PC as a primary network access device, the small size and light weight devices offer a good solution for mobile access. The PalmPilot offers both a traditional wireline modem for use with a standard phone line, or a GSM compatible modem for connection to a cellular phone. Most common digital mobiles are supported by the makers, Option.

A nunmber of options are available to Windows CE PDA owners, due to the devices PCMCIA support. Ericsson also offer an integrated WinCE device tha plugs directly into an Ericsson handset to provide connectivity.

7) What about software?

All standard communications software will work with wireless connections on a notebook, whie PDAs have their own custom software. Windows CE ships with cut down web and Email clients, and the PalmPilot has several web browsers available, in addition to third party POP3 and IMAP4 Email support.

8) What does it cost?

Allow in the vicinity of $400 – $500 for the hardware to connect a notebook or PDA to a cellphone, plus the costs of network access. Of the three GSM network providers in Australia, Telstra, Optus and Vodaphone, both Telstra and Vodaphone have agreements with national ISPs to provide an access number for mobile users to dial which gives Internet access for no additional charge, apart from the standard timed mobile phone call cost. Optus currently has no ssuch agreement at this stage so Optus users should add the cost of connecting to their usual ISP to their call costs.

9) What are the drawbacks?

The biggest barrier to widespread adoption of wireless data connectivity remains the high cost of network access time. The per minute charges which are acceptable for a quick phone call are crippling for applications such as web surfing. The low data throughput rates, and less than 100% geographical coverage also serve to hamper the widespread deployment of wireless data solutions.

10) What about the future?

There are no definite plans to roll out either two-way paging or Ricochet modem infrastructure in Australia, so for a viable alternative to GSM users will need to wait for technologies such as satelitte data services that are slated to appear over the next few years, but don’t expect these to be any cheaper than GSM, although their is a potential to increase data rates up to 2Mbps. Wireless network connectivity is an exciting development for Internet users, but the costs and technical drawbacks will slow the widespread introduction of these technologies.