Wireless Computing
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Introduction to Wireless

Wireless Technologies

Interference

Network Security

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Wireless Technologies

Internet Architecture - The 802.11 Standard - Bluetooth

IEEE 802.11

There are many advantages to the development of the IEEE 802.11. It makes many different appliances from different vendors compatible. Companies can develop products faster because the producers for 802.11 have already gotten rid of bugs. It works for future products. It lowers costs because vendors do not need to develop and support subcomponents.

802.11 Specifications

IEEE 802.11 functions with a radio card and an access point. The range for 802.11 depends on the method of transmission and the obstacles between the client and the access point. It tends to be from 100-200 ft. Multiple access points and/or extension points are used to obtain a greater range. IEEE has a capacity of 1 or 2 Mbps. For frequency hopping, IEEE 802.11 hops between 2.4GHz and 2.483 GHz. For Direct Sequence, it uses a minimum of 11 chips.

The 802.11 standard includes:

  • support of asynchronous and time-bounded delivery service
  • continuity of service within extended areas via a distribution system
  • accommodation of transmission rates of 1 Mbps and 2 Mbps
  • support of most market applications
  • multicast services
  • network management services
  • registration and authentication services

802.11 has applications both inside (offices, banks, shops, malls, hospitals, manufacturing plants, residences) and outside (parking lots, campuses, building complexes, outdoor plants).

802.11 solves some issues with normal wireless:

Wireless Problem802.11 Solution
Relies on batteries, may drain quicklyLow power, can be put on standby (puts radio to sleep and wakes up periodically)
Not a lot of bandwidth, which leads to lower data ratesCompresses data
Transmits over a larger area, which is then too large to protectDeveloped security mechanisms for all 802 series
Destination address is not the same as the destination's locationUses Independent Base Service Set and Extended Service Set networks

Independent Base Service Set (IBSS) networks use at least 2 wireless stations and, therefore, can be constructed quickly. These tend to be used in a single room, a sales floor, or a hospital wing. Extended Service Set (ESS) networks cover large coverage networks. There are three kinds of mobility. The first is just mobility within a BSS. The second is moving from one BSS to another BSS, but staying within the same ESS. The third is moving from one BSS to another BSS in a different ESS.

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