Published 16 Jun 2017
Wireless modems are communication devices that provide a possibility for a system to connect to the network without any physical cables, like in the case of Ethernet cables. A wireless modem connects to a wireless network instead of to the telephone system. When connecting with a wireless modem, a system is attached directly to the wireless ISP (Internet Service Provider) and Internet browsing becomes available. Wireless modems operate at speeds comparable to dialup modems, not anywhere near the speed of broadband Internet connections.
The connection is performed through wireless local area network (WLAN). The connection to WLAN is performed using different types of protocols: cellular, satellite, or WiFi, which provide internet services. The protocols of connection are the primary difference between wireless modems and dial-up or DSL modems, which perform internet connection through telephone lines, and cable modems use cable TV lines for connection.
In mobile devices wireless modem is represented by PCMCIA card (in laptops), which accesses the Internet through public “hotspots.” Hotspots are specific geographical regions, within which WLAN allows public access to the Internet using wireless modems.
Each wireless modem is designed to access a specific wireless network. Networks which support wireless modems include: CDPD (Cellular Digital Packet Data), GSM GPRS (General Packet Radio Service), GSM EDGE (Enhanced Data GSM Environment), and some others. CDPD (Cellular Digital Packet Data) is a “specification for supporting wireless access to the Internet and other public packet-switched networks over cellular telephone networks.” CDPD supports TCP/IP and Connectionless Network Protocol (CLNP). CDPD utilizes the RC4 stream cipher with 40 bit keys for encryption (SciTech). GPRS (General Packet Radio Service) is a “specification for data transfer on TDMA and GSM networks. GPRS utilizes up to eight 9.05Kb or 13.4Kb TDMA timeslots, for a total bandwidth of 72.4Kb or 107.2Kb. GPRS supports both TCP/IP and X.25 communications” (Van Horn). EDGE (Enhanced Data rate for GSM Evolution) is a specification for data transfer on GSM networks. “EDGE features a packet capability, EGPRS (Enhanced General Packet Radio Service), and a circuit switched capability, ESCD (Enhanced Circuit Switched Data)”. EDGE packs up to “69.2Kbps into eight timeslots, for a total theoretical bandwidth of 473.6Kb” (Mobile Internet).
Various wireless networks use proprietary protocols, and wireless modems are certified as compatible with certain architectures. Protocols differ by connection speed and quality (passing ability). The slowest protocols are GPRS, EDGE, and CDPD, which lose in connection speed to dialup modems. Cellular UMTS and 1xRTT wireless networks provide great connection speed (about 300 Kb per second). The latest technologies claims to reach the connection speed of 400 to 700 kb per second, which provides a great networking system and introduces a more efficient alternative of broadband systems. Further development in this area promises even greater speeds with new systems like HSDPA and EVDV.
WiFi (wireless fidelity) network is growing in popularity these days, and it allows accessing the internet at approximately 400 kb per second. WiFi connection access points are distributed also in hotspots or specifically set up internet cafés. A recent development of newer technology, which advances WiFi system, is called WiFiMax. Based on the IEEE 802.16 Air Interface Standard, WiMax delivers a point-to-multipoint architecture, making it an great method for carriers to deliver broadband to locations where wired connections would be difficult or costly. Basically, WiFiMax is an advance system of WiFi which provides new opportunity for both internet providers and users, significantly reducing station costs for distributing the signal as well as providing an opportunity to cover wide ranges of geographical locations.
“Emerging Technologies : Wireless Networks.” Technology. 6:1. 2005.
“GPRS in practice; a companion to the specifications.” SciTech Book News, June, 2005.
“GSM/3G driving mobile broadband networking.” Mobile Internet, Feb, 2005.
Mathias, Craig J. “Will “Mobile, Broadband Wireless” Redefine Access?” Business Communications Review. 30:3. March 2004.
Van Horn, R. “Technology – Modems: Wired versus Wireless.” Phi Delta Kappan. 82:8. 2005.