Wireless Modem

Gone are the days when one would need to be wired to a computer table in order to browse the internet. Dial-up phone modems have now given way to wire-less modems that:

  • Allow internet access within a specified range.
  • Provide a secure network connection.
  • Can be connected to more than one computer at the same time.
  • Allows sharing of files among computers registered in that network.
  • Provide speeds and connectivity comparable to other broadband or dial-up connections.

History:

Earlier analogue mobile phones provided slow speed internet via a standard RJ11 telephone socket.

  • They were succeeded by digital phones that provided better speed and had inbuilt modems.
  • Next, HSCSD was introduced which used multiple GSM channels for a better speed.
  • In all these models, the mobile phone network did not provide internet access.
  • Dial up ISP’s were required in conjunction with the phone sets for internet access.
  • The advent of “packet- switching technology” allowed simultaneous use of voice and data connection.
  • This enabled internet browsing through phones.
  • Subsequent models have succeeded in achieving better speeds and better technology based on similar principles.

Connection:

External modems may connect via:

  • Serial cable or Ethernet
  • USB
  • IrDA Infrared
  • Bluetooth wireless.

A wireless modem may:

  • Attach to your mobile or land-line connection.
  • Attach directly to your laptop or desktop through a USB port.
  • Be used as data modems to provide a gateway between data network technology and PPP (Point to Point Protocol).
  • Be used in WiFi or WwiMax standards
  • Be coupled with VoIP technology to facilitate telephonic capability.

Wireless modems allow computers to connect to a wireless local area network (WLAN) sans any external cabling like Ethernet.

These modems may use one of the following three protocols in order to provide an internet service:

  • Cellular
  • Satellite
  • WiFi

General Features:

While purchasing and installing a wireless modem at home or in a small office space, the following features should be considered:

  • What are the internet speed, range and connectivity?
  • Does the modem support protocols like Ethernet, CPCD, GPRS, ISDN, EVDO and WiFi?
  • What is the frequency band specified?
  • Does it have a Radio technique facility that offers direct sequence spread spectrum and frequency hopping?
  • How many channels can be transmitted or received?
  • What is the Maximum Signal Strength?
  • Does it have a Full duplex or a half-duplex capability?

Wireless Modem Interface:

This includes the following four parts:

  • PCMCIA
  • Compact Flash
  • USB
  • Serial Port

Common Terminology:

PCMCIA: Is used for mobile applications in the form of a card. PCMCIA provides internet access through public “hotspots”.

Hotspots: These are geographical areas where public internet access in provided by wireless modems. They may require a registration fee or may have free access.

WiFi: stands for “wireless fidelity” and is the most popular network for mobile wireless modems. It delivers a relatively better speed.

Wireless Modem Networks:

Wireless modems are network specific and are supported only by specific networks. These are:

  • CDPD (Cellular Digital Packet Data)
  • GSM GPRS (General Packet Radio Service)
  • GSM EDGE (Enhanced Data GSM Environment)

Requirement and Recommendation:

A high powered wireless modem is recommended when:

  • Signal strength shows less than three bars
  • Indoor web access is required
  • There are multiple physical obstacles between the computer and access point
  • The computer is more than 200 feet away from the outdoor access point
  • A wireless network adapter is absent in the computer

Tips for Best Results:

  • Disable internal wireless card on laptop for better sensitivity and connection.
  • Place the wireless modem near a window or a wall that is closest to the access point.
  • Make sure that the omni antenna is facing straight up.
  • Consider an outdoor wireless modem if the space is small and crowded
  • Configure your WLAN on a different channel compared to access point for lesser overlap and interference.