Mobile Computing vs Wireless Networking

Mobile Computing vs. Wireless Networking Mobile computing is based on wireless networking and helps one to invoke computing services on remote servers while on the move: be it be office, home, conference, hotel, and so on. Wireless networks can be classified into two basic types. One is an extension of wired networks. It uses fixed infrastructures such as base stations to provide essentially single hop wireless communication with a wired network as illustrated in Fig. 2.1 or a two-hop wireless cellular communication with another mobile as explained earlier in Fig. (Refer Chapter 1 Architecture of mobile telecommunication). The other type of wireless network is an ad hoc network. An ad hoc network does not use any fixed infrastructure and is based on multi-hop wireless communication as shown in Fig. 2.2. One popular example of a fixed infrastructure wireless network is a Wireless LAN (WLAN) that implements the IEEE 802.11 protocol. Observe from Fig. 2.1 that only the last hop is through the wireless medium. An access point (AP) provides the last hop connectivity of the mobile nodes Figure 2.1 Wireless network based on fixed infrastructures. to a wired network. All communication goes through APs which perform bridging* between the wireless and the wired mediums. A station must be recognized by an AP to be able to connect to the network. The AP may require authentication and this in turn is used as the basic means to keep out unauthorized users.