Wireless Networks: Technology and Applications - Essay Example

Wireless networks The wireless network has standards which help to regulate the connections that are seen in the wireless networks. These standards have their own advantages and disadvantages over the other networks. In this paper we will look at 802.11 vs Bluetooth wireless networks. Bluetooth Bluetooth was a technological idea conceieved by Ericsson Mobile Communication in 1994, it is a wireless communication based on radio system that enable devices to communicate in a short range. Other mobile device venodrs such as Nokia, IBM, Toshiba and Intel came up with a group known as Special Interest Group (SIG) (Erina & Francesco). Bluetooth enables compartible devices such as portable computers to communicate and act as a bridge to other networks. Bluetooth is in the range of application devices known as WPAN (Wireless Personal Area Network). Buetooth replaces cable connection between devices such as printers, joysticks, keyboard, mice among devices. The original intention of this technology was so that it would be possible to connect mobile phones to headsets. It has grown to be popular wireless connections for many devices. When compared to WiFi, it comes out as a more user-friendly technology. Bluetooth technology operates in the same frequency range with the 802.11b signals. This is one of the disadvantages that come with Bluetooth as it brings interference to this network. Bluetooth has taken more time to come to be accepted in the market because of the fact that it has low data transfer rate. Initially, it was designed to be used in the connection for devices like printers and mice and also used for data transfer. Fig 1.0 Bluetooth coverage setup 802.11a This wireless network has capabilities of transmission speeds going to 300Mbps. The frequency range of this technology is 2.4GHz to 5.0 GHz. It is the most recent wireless technologies standards. It is well suited for connections that are meant for streaming purposes and also for connections which are meant for heavy downloads and uploads. The beauty of this technology is that it has backward compatibility with older standards like 802.11g 802.11b This standard operates in 2.4GHz band only. There are no other ranges that the network operates. The main advantage of this network standard is that weaknesses of signals due to distance are really solved. It is suitable for networks where the range is far more important than the bandwidth. It has better range and penetration. Given the same distance and obstacle, the throughput will be seen to degrade. This connection is well suited for connection used for Internet access and general web surfing. For the connections which are used for LAN (file sharing and video streaming), then this network is not the recommended one. The 802.11g and 802.11a are well suited for this. Clients using the 802.11b network and operating in an 802.11g will force the access points to transmit signals in B mode and in so doing will nullify the advantages that come with G network. A laptop batter will last longer if the laptop is operating in this mode. 802.11g This standard is popular in the high bandwidth it uses. The operation of the bandwidth in which it operates is 54Mbps compared to 11Mbps that are used by 802.11b networks. The advantages that come with this network standard include the fact that it is compatible with the other standards. This means that a laptop with the 802.11g card is still in a position to access the B and A networks. Another advantage is that it is cheaper when compared to the standards. 802.11 wireless connection setup Functionality differences of bluetooth and 802.11 IEEE 802.11 wireless network and Bluetooth both operate in 2.4 GHz frequency range and they to uses frequency hopping sprectrum (FHSS). When IEEE 802.11 wireless networks is co-located with 802.15 WPANs can interfere each other. While Bluetooth with the new released version which uses adaptive frequency hopping (AFH) technique has less chance of being intefied with. Network Size Bluetooth has a maximum of 8 devices 2 to its network where seven are slaves while one the master. The network block of a bluetooth device can only accommodate 8 devices while IEEE 802.11 has unlimited number of devices connected in its network block. Bluetooth operates in a range of less of 30 feet while 802.11 covers up to 200 feet therefore bluetooth needs more access point to cover an office as opposed to 802.11 which may just require one or two access point to cover an office. Power Consuption The power consuption of bluetooth is lower compared to consuption of power by 802.11 devices. Bluetooth also offers radio link power control this controls power depending on the strength of the signal received by the device by requesting other network devices to adjusting their power to radio level. This ensures that the signals received are wthin the preferred range. 802.11 protocol power consumption has defferent consumption level but one device should have Equivalent Isotropic Radiated Power (EIRP) of 10 mW and another of 100mW. The table below tabulates the power consumption of the bluetooth Maximum output power Nominal output power Minimum output power 100 Mw (20 dBm) NA 1mW (0 dBm) 2.5 mW (4 dBm) 1 mW (0 dBm) 0.25 Mw (-6 dBm) 1 mW (0 dBm) NA NA Table 1.0 power limitation for bluetooth devices Spatial Spatial is another application area of Bluetooth and 802.11 which is the overall data transfer speed and used transmission area. Bluetooth, in a range from 10 meters, can be allocated 20 different Piconets with maximum overall data transfer speed of 400Kb/s (Souissi & Meihofer, 2000). While 802.11 in 100 meters has a speed of 31.4 Mb/s hence the bluetooth has small data rate transfer compared to 802.11. Network Creation Speed The speed at how devices of the same network link to each other is referred to network creation speed. Bluetooth in devicovering devices within their coverage area uses Inquiry and the Page procedures, this method enables the devices to discover other bluetooth devices within its range. The MAC addresses of other devices within a coverage area are discovered by the master device. The maximum number of nodes in a Piconet which is 7 slaves devices it is done by periodically inquire for new devices. The devices are paired or connected to the master devices by an authontication key. This is a security mesuare to ensure that only authorized devices have access to the network. IEEE 802.11 in the speed of how the devices in the same network link or are set up is determined by scanning, Authenticating and Association procedures. Regarless of the mode of the device, the scan procedure to discover the MAC addresses and other variables or details of the 802.11 devices within the coverage area. There is different scanning time span for active and passive mode where passive mode. The adhoc network, authetication procedure is optional after scan procedure. Authentication procedure follows after scan procedure in an insfrastructured network if the access point is dicovered after this Association procedure. There are two authentication procedures Open System Authentication (OSA) and Shared Key Authentication mode (SKA). The access point AP sends messages asking for authentication where a share password is shared and encrypted. Association mode exists within the active phase of the two point in connection. This application differences can be summarized in the table below: BLUETOOTH IEEE 802.11 Max number of devices in the basic cell 8 active devices; 255 in park mode Unlimited in ad hoc network (IBSS);up to 2007 devices in infrastructured network. Extension of the basic cell Scatternet ESS Maximum signal rate 1 Mbs 11 Mb/s in 802.11b, 54 Mb/s in 802.11g Procedures used for the network setup Inquiry, Page Scan, Authentication for ad hoc; Scan, Authentication and Association for insfrastructure Nominal range 10 m 100 m Spatial capacity About 100 kb/s.m2 15 kb/s.m2 Average speed in network setup without external interferences 5 s + n 1.28s, where n is the number of slaves in the Piconet, ranging from 1 to 7 n.c 1.35 ms for an unsaturated network, c probed channels (1 Read More