HOT TOPICS: WIRELESS TECHNOLOGY
Wireless Works - what are you going to do about it?
Two forces are driving business communication:
||• Users mobility
||• The need for information
To satisfy the mobility requirement, the last 10 years has seen extraordinary development in mobile telephony, network infrastructure
now covering the developed world, and explosive growth in the size and reach of the Internet.
Recent developments in handset technology: larger displays, better input devices and longer battery power, have rendered mobile phones
appropriate terminal devices for Internet access. On the Internet side technology such as WAP and multiple-device-support websites
indicate the readiness for the convergence of mobility and information access.
There is some confusion, however, in the "big picture" for wireless communications in the future. Both mobile telephony and wireless
LAN's are vying for selection as wireless solutions.
In Europe the development of a coherent mobile phone strategy is mature and the inevitable march towards ubiquitous 3G services
is underway. In the US the picture is more fragmented with suppliers of wireless LAN products promoting that technology as the
correct solution for high-speed, mobile data communication.
There are benefits to both approaches and the astute IT manager will blend them into the optimal solution for their company.
Wireless data communications is undergoing immense change at the present time as the technology moves from an analogue, voice-based
system to a digital, data-based system. The convergence of voice and data on a digital infrastructure enables significant economies
to be realised.
The development of wireless telephony can be depicted as follows:
We are currently in the 2.5 Generation time period dominated by GSM voice phones
but with GPRS data capability. At the present time most transmission of data
across GSM networks uses the SMS system, an connection-oriented data-packet technology.
GPRS (General Packet
Radio Service) offers the first real mobile telephony data transmission standard.
At the core of all GPRS systems is a GSM network at the present time but its
longevity is ensured as it is part of a long-term strategy that will see its
services morph into 3G services.
The attributes of GPRS are:
||• "Always on" packet switched service which means that customers are only billed for data sent and not for connect time. This is obviously
beneficial for mobile workers who work a shift and need to "stay connected" during that time.
||• Internet connectivity with the ability to transmit and receive IP packets to and from the Internet.
||• Realisable data speeds in the area of 35kbs (170kbs theoretically), approximately three times faster than current circuit-switched data
As equipment is upgraded, GPRS services will be provided over EDGE facilities (Enhanced Data rates for GSM Evolution). EDGE utilises a
new modulation technique that will more efficiently use the radio spectrum. EDGE represents the start of the transition to 3G systems
An overview of the migration from current "push" services to the long-term mobile multimedia environment is as follows:
• Push Info
• Internet/ Intranet Access (Pull)
• Full e-mail with Graphics etc
• Multimedia "Push"
• Information services
• Mobile Tele-working
• Remote Services
• Health Care diagnostics
• Industrial Applications
The development of mobile communications is developing rapidly and over the next three years dramatic changes will take place in the
type and capabilities of services offered by telecommunications companies. To take advantage of the "quantum leap" in mobile
communications that 3G services represent, experience with 2G services is essential.
Virtually all local area networks utilise the IEEE 802 specifications. By far the most ubiquitous is the 802.3 specification using
universal twisted pair (UTP), that is: cabling that adheres to the Category 5 (CAT 5) specification for 100Mbs transmission over two
Wireless LAN technology is built around the IEEE 802.11 specifications. These determine the characteristics of a wireless service that
will support the same TCP/IP network traffic but with no physical connection.
There are several variants of 802.11 in popular use today. 802.11b is the most widespread. It uses a 2.4Ghz frequency and has a
specified transmission speed of 11Mbs over a radius of about 500M. In reality a 5Mbs throughput over about 100M may be realised.
802.11a uses a 5Ghz frequency that supports faster communication - up to 54Mbs, but the distance specifications is decreased to 100M.
In reality a 50M radius will provide reliable communication.
802.11g is an upgrade to the 802.11a that pushes data in the 2.4Ghz frequency band at 54Mbs. It has the distance of the lower frequency
but the data throughput of the higher frequency.
IT managers considering acquisition of wireless LAN PCs should decide on the standard that will be used, or purchase dual-band cards
capable of operating multiple protocols.
Being a shared access medium, wireless LANs introduce a wide variety of concerns, not the least of which is security. Deployments of
private installations must protect the network from rogue devices that could consume resources or compromise the organisation's security.
The advantage of Wireless LANs include:
||• access by notebook computers providing a standard terminal device with a full keyboard and extensive screen
||• reduced costs with no common-carrier
The IT Manager considering wireless solutions must first develop a good appreciation of the options available. Selection of the
optimal solutions will involve the following decision criteria:
||• device preferences
- is a Notebook PC required that will allow the user to "surf the Web",
or write elaborate emails, or is a handheld device that is easier to transport
||• will users typically be in an
office environment that might be expected to have a wireless LAN or are
they more likely to be
traveling around and need to be more self-sufficient?
||• what are the costs for the various options - do common carrier tariffs make the mobile telephony option too expensive?
||• what are the security considerations - does wireless access to the corporate network "break" the company's security policy?
* This discussion covers the 802.11 or Wi-Fi products as the main option in the wireless LAN arena. Bluetooth and IrDA are considered
inter-device communications mechanisms for very localized application. Bluetooth does, however, have an important application in the
connection of devices to 3G services.