Wireless peripherals

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Computer Studies wireless router

A wireless print server is usually an access point with USB ports that can connect printers, the printer can also be connected using an Ethernet port, sharing and printing can be configured on the access point or print server via a web-based interface, wireless media centers are also used to share music and video on a network used mainly in homes or internet cafes it can stream audio or video to devices from a media library or the internet, these devices can connect directly to the computer or they can be connected to TVs, Stereos or DVRs some can have internal storage to store MP3s and video, wireless presentation gateways can be used to connect to overhead projectors used in the business environment, other devices can include IP phones, wireless video surveillance cameras, wireless boosters or extenders, gaming devices such as the Microsoft Xbox, Nintendo Wii, Sony play station 3, PDAs, Laptops, Tablet PCs, wireless bridges, wireless switches and controllers, point of sale and inventory systems, barcode readers used in factories and supermarkets, keyboards and mice, storage systems, hotels using hotspot gateways.


Bluetooth was developed as a protocol for use in wireless personal area networks, released as the IEEE 802.15 WPAN standard, devices communicate in Ad-Hoc networks called Piconets, Bluetooth uses FHSS or Frequency hopping spread spectrum modulation using the 2.4 GHz frequency range and changes frequency at 1600 hops per second between 79 different frequencies, it uses very low power and a low range.

Device class Signal strength Range
Class 1 100 mW 100 meters
Class 2 2.5 mW 10 meters
Class 3 1 mW 1 meter

The Bluetooth special interest group is a group of manufacturers dedicated to ensuring interoperability and adherence to standards, Bluetooth enabled devices include PDAs, Cell phones, Laptops, Tablet PCs, Headphones and Transmitters, Bluetooth uses a unique device address to authenticate devices, provides authentication at the data link layer of the OSI model, the key length is selectable between 8 - 128 bits encryption algorithms, the key size is usually hard coded at the factory, devices can be secured and set to undiscoverable by other devices, Bluetooth devices pair with each other via a shared pin enabling devices to trust each other, encryption can be required before connection is allowed between devices, Bluetooth as many security weaknesses there's no process for managing issue validation or revoking link keys and shortcomings in encryption and authentication protocols, weak key strength, repartition of initialisation vectors, there are vulnerabilities in the protocol stack, encryption and authentication can be overcome and is not required for communication between devices, broadcast traffic is not encrypted by default, service discovery can be discovered on another device by default and it's easy to sniff and spoof Bluetooth traffic. For more on

Infrared technologies

Infrared technologies are used with small personal electronic devices, they are used to transmit small amounts of information between devices, both devices are required to have infrared ports and depend on line of sight to communicate with each other, you can do small file sharing and limited peripheral sharing, data rates average 115.2 Kbps, devices referred to as a primary initiates the connection and a secondary device replies, computers and PDAs are normally primary devices and devices like printers are secondary devices, infrared is used with PDA synchronisation to computer, phone books, calendars, e-mail, mobile phones, also used with point of sale, barcode scanners and inventory equipment. For more on Infrared

Cell phones

Cell phones use several technologies to connect to a cell network, analogue technologies are not widely used any more they are not secure, unreliable, digital technologies have now become standard Cell phones are usually classified in one of three categories 1G the first generation technologies, out dated and not used anymore had limited data capabilities, 2G the second generation is still widely used, divided into TDMA or Time division multiple access and CDMA Code division multiple access categories, common 2G technologies iDen and GSM the services are commonly called PCS services, 3G or third generation, high data rates with the ability to transfer voice and data simultaneously, popular in multimedia-enabled Cell phones. For more on Cellphones

Connecting with wireless PDAs

PDAs and smart phones are in widespread use, the devices can connect to wireless networks for e-mail, news, using web browsers, with a variety of technologies Bluetooth, Infrared, 802.11 protocols, PDA devices have Mini PC or SDIO devices built into them, Cell phones can use Cellular technologies many of the vendors such as Sprint, Cingular, Verizon have their own broadband services, PDAs have mini operating systems that support wireless connections with e-mail clients, web browsers, the newer PDAs have built in support for the WiMAX standards for wide area broadband. For more on PDAs


Radio frequency ID used to track inventory and control equipment, small tags are attached to items and a signal is sent to a central receiver, it as a limited range, there are two types of systems used Active and Passive, Active systems have an internal battery, and transmit stored information when queried by the reader, their range can be from a few inches to a few hundred feet, Passive systems have no internal power, they receive transmitted signals from a central station and use those signals as power to transmit the signal back to the central station, there is a limited range around 12 feet, some systems require a pass-code for authentication, this information is not encrypted so can easily be sniffed, and it's easy to spoof transmitted data with RFID and it can then be retransmitted. For more on RFID


Zigbee is a wireless technology designed for industrial purposes for automation control, and for monitoring systems, it uses the 802.15.4 standard and uses DSSS or Direct sequence spread spectrum, the Zigbee alliance is a group of manufactures dedicated to ensuring interoperability and adherence to standards for Zigbee devices, devices can be networked in a WPAN architecture and contain up to 65,536 nodes, it's not interoperable with Bluetooth or 802.11 standards, it can be used in a home automated system light switches, alarm timers etc, devices are low power and can run on AA or AAA batteries. For more on Zigbee

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