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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 ISPs 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:
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.
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