ABC: An Introduction to Wireless
Get an overview of the promise and limitations of wireless communications
- What does "wireless" mean?
- What's the difference between wireless and mobile?
- Today's wireless technology—cellular networks
- Tomorrow's wireless technology
- Wireless networks
- Benefits of wireless communication
- Challenges
- Recent improvements
- Getting started
- Buzzwords
- Hot questions
- Checklist – 8 things you need to know
Buzzwords
- Bandwidth
The total information flow on a telecommunications medium over a given time. The greater the bandwidth, the quicker the transmission or retrieval of information.
Bandwidth is typically measured in increments of Kbps (kilobytes per second), Mbps (megabytes per second) or Gbps (gigabytes per second).
A 56Kbs modem can easily move 16 kilobytes in one second.
- BlackBerry
BlackBerry provides a variety of wireless PDAs and software to keep mobile professionals connected to the people, data and resources they depend on. Its push-based wireless technology integrates e-mail, phone, SSMS, a browser, industry-specific applications and organizer applications on a single device. It also allows you to view e-mail attachments in popular document formats. BlackBerry supports various service providers, and 50 networks in 30 countries.
- Bluetooth
Bluetooth is an industry-standard specification for wireless networks, with a range of about 10 feet and a maximum throughput of about 1Mbps. A Bluetooth device, which incorporates a base-band processor, a radio and an antenna, uses radio signals to send information from one Bluetooth device to another through the air, at a frequency of 2.4 gigahertz.
- Firewire
IEEE 1394 (a.k.a. FireWire) is a type of cabling technology for transferring data to and from digital devices at high speed. Some professional digital cameras and memory card readers connect to the computer over FireWire. FireWire card readers are typically faster than those that connect via USB. FireWire was invented by Apple Computer but is now commonly used with Windows-based PCs as well.
- GPRS
GPRS is a digital cellular technology that transmits both voice and data, at a throughput of up to 100Kbps. Its range varies from several hundred yards to several miles, depending on the density of buildings and other obstructions. GPRS is a standard throughout Europe and widely deployed elsewhere in the world, including the United States and Canada.
- PCS
Much like a cellular technology, Personal Communications Services (PCS) send calls from transmitter to transmitter as a caller moves. The difference is that PCS uses its own network, not a cellular network, and offers fewer "blind spots" than cellular.
- PDA
A Personal Digital Assistant (PDA) is a handheld computer that provides a calendar and organizer for personal information. A PDA normally contains at least one database with names and addresses, to-do lists and a notepad. Some PDAs, such as the BlackBerry, provide phone and e-mail capabilities.
- VoIP
Voice over Internet Protocol is IP Telephony. It involves the transmission of telephone and fax calls over a data network like the Internet.
- WAN
Wide area network – can be wired or wireless
Wired example: a network connecting the computer LANs in a company's multiple office locations
Wireless example: Cellular phone network that covers areas as large as several countries
- WAP
Wireless Application Protocol (WAP) is a set of protocols used to transfer data to wireless devices. WAP-enabled devices provide wireless users with a limited version of the Web designed to work on the small black-and-white screens of phones and PDAs.
- Wi-Fi
Wireless fidelity (Wi-Fi) is another name for IEEE 802.11b, a trade term promulgated by the Wireless Ethernet Compatibility Alliance (WECA). "Wi-Fi" is used in place of 802.11b in the same way that "Ethernet" is used in place of IEEE 802.3. Products certified as Wi-Fi by WECA are interoperable with each other even if they are from different manufacturers. A user with a Wi-Fi product can use any brand of Access Point with any other brand of client hardware that is built to the Wi-Fi standard.
- Wireless LAN
A wireless LAN (WLAN) is a local area network (LAN) without wires (see LAN). WLANs have been around for more than a decade, but are just beginning to gain momentum because of falling costs and improved standards. WLANs transfer data through the air using radio frequencies instead of cables. They can reach a radius of 500 feet indoors and 1000 feet outdoors, but antennas, transmitters and other access devices can be used to widen that area. WLANs require a wired access point that plugs all the wireless devices into the wired network.
Hot questions
Anil Khatod, president and CEO of Alpharetta, Ga.-based AirDefense, answered questions about wireless technology. AirDefense is an innovator of wireless LAN security and operational support solutions.
Q: How will wireless technology overcome the limited channels and interference in highly dense areas?
A: Technology advancements in the form of dynamic RF management (intelligent power control and interference avoidance), along with spatial division multiplexing, can significantly expand the capacity available today. Further out, higher density modulation schemes and multi-radio, mesh network architectures may also come into play.
Within the enterprise, voice over IP (VoIP) may become the dominant application of wireless LANs, followed by traditional Web and e-mail usage. Hotspot applications will likely remain dominated by Internet access.
Q: Is the security risk in wireless higher as compared to cabled network even when a similar degree of protection is provided in both cases by means of encryption or other such methods?
A: Yes, the implications of an untrusted physical layer are numerous. Many legacy protocols never considered these implications and may be vulnerable as a consequence without appropriate modification or configuration requirements. Further, the host or end-user is often the weakest link in the security chain and the open nature of wireless may exacerbate this weakness.
Q: What is the biggest mistake companies are making concerning the implementation of wireless?
A: The biggest mistake is not being aware of their wireless environment. Many secure wireless deployments ignore other devices that may be within or around the deployed environment. These devices include rogue APs and stations and other devices that existed prior to the wireless deployment. Having an ongoing awareness of all wireless devices, how they're behaving and interacting is essential for maintaining the security and operational stability of a wireless network.
Q: Can a wireless system be hidden from all discovery?
A: Some wireless protocols can be configured to not speak until spoken to. Bluetooth can be configured in such a way. However, by definition, 802.11a,b and g by protocol definition must make themselves known to devices that may communicate with them. If networks could be configured not to be discovered until a legitimate device attempts communication, as soon as they begin communication with that device at the very least their radio emissions would be detectable if not framed data.
Concealing a wireless network from discovery is typically accomplished through physical barriers such as window coatings or other RF barriers.
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