Wireless WAN

A wireless wide area network (Wireless WAN OR WWAN), covers a much more extensive area than wireless LANs. Coverage is generally offered on a nationwide level with wireless network infrastructure provided by a wireless service carrier (for a monthly usage fee, similar to a cellular phone subscription). While Wireless LAN are used to allow network users to be mobile within a small fixed area, Wireless WAN are used to give Internet connectivity over a much broader coverage area, for mobile users such as business travelers or field service technicians.

Wireless WAN allows users to have access to the Internet, e-mail, and corporate applications and information even while away from their office. Wireless WAN use cellular networks for data transmission and examples of the cellular systems that are used are: CDMA, GSM, GPRS, and CDPD. A portable computer with a Wireless WAN modem connects to a base station on the wireless networks via radio waves. The radio tower then carries the signal to a mobile switching center, where the data is passed on to the appropriate network. Using the wireless service provider’s connection to the Internet, data communications are established to an organization’s existing network. Wireless WAN use existing cellular telephone networks, so there is also the option of making voice calls over a Wireless WAN. Both cellular telephones and Wireless WAN PC Cards have the ability to make voice calls as well as pass data traffic on Wireless WAN networks.

Wireless WAN by definition operates over a small, “local” coverage area, normally about 100 m in range. They are typically used in buildings to replace an existing wired Ethernet, or in a home to allow multiple users access to the same Internet connection. Other wireless LAN coverage areas can include public hotspots in coffee shops or some city neighborhoods. Wireless WAN covers a much “wider” area, such as wherever the cellular network provider has wireless coverage. Typically this is on a regional, nationwide, or even global scale. Using a Wireless WAN usually gives the user access to data wherever they go and is one of the biggest advantages of a wide area network.

Wireless WAN speeds differ depending on the technology used. GPRS networks offer a maximum user data rate of over 115 kbps if all eight timeslots in a cell are allocated for data transmission, (one timeslot can provide between 9 and 21 kbps). However, a realistic and consistent user data throughput rate of 30–50 kbps is expected and seen in practice, when 4 timeslots are used, as currently supported by most networks. This may be increasing in the future. These timeslots are shared with the voice traffic on the GPRS network.

Data Speeds: Speed on CDMA networks were initially available at speeds of 14.4 kbps, but have increased to a maximum throughput of 153 kbps as carriers have implemented CDMA2000 1X (1xRTT) networks. This gives the user typical throughput speeds of 40–70 kbps, in addition to doubling the voice capacity of the carrier’s network. Future Wireless WAN technologies, like CDMA2000 1xEV-DO, provide peak data rates of up to 2.4 Mbps in a standard 1.25 MHz CDMA channel. UMTS, also known as WCDMA (Wideband CDMA) is another approved next generation standard which utilizes one 5 MHz channel for both voice and data, offering data speeds up to 2 Mbps.

Data Security: Security is one of the most important features when using a wireless network. Security is one of the biggest strengths for cellular wireless networks (Wireless WAN) and one of the biggest weaknesses in 802.11 networks (WLANs). 802.11b networks have several layers of security; however there are weaknesses in all of these security features. The first level of security is to have wireless LAN authentication done using the wireless adapter’s hardware (MAC) address. However, this alone is not secure because the MAC address of a wireless client can easily be falsely created. Security can be increased on wireless LANs by using shared key authentication. This shared key must be delivered through a secure method other than the 802.11 connection. In practice, this key is manually configured on the access point and client, which is not efficient on a large network with many users. This shared key authentication is not considered secure and is not recommended to ensure security.

Another weakness in an 802.11 network is the difficulty in restricting physical access to the network, because anyone within range of a wireless access point can send, receive, or intercept frames. WEP (Wired Equivalency Protocol) was designed to provide security equivalent to a wired network by encrypting the data sent between a wireless client and an access point. However, key management is a significant problem with WEP. WEP keys must be distributed via a secure channel other than 802.11. The key is normally a text string that needs to be manually configured on the wireless access point and wireless clients, which is not practical to a large network. There is also no mechanism to change the WEP key regularly or periodically, so all wireless access points and clients use the same Wireless LANs vs. Wireless WANs Comparing Wireless LANs and WANs manually configured WEP. With several wireless clients sending large amounts of data, without changing the WEP key, it is possible to intercept data traffic and determine the WEP key. This would allow a hacker to intercept and decrypt the data traffic.

A Wireless WAN however operates in tightly regulated frequency spectrums and all operators must be licensed to operate in this frequency. This implies much better data security and protection, since licensed operators have to follow government regulations for wireless access. In contrast to the security weaknesses in 802.11 networks, cellular Wireless Wan networks are extremely secure. These networks incorporate military technology and sophisticated encryption and authentication methods.