Wireless LAN Technology and Its Construction - Essay Example

Wireless LAN Technology and its construction Technical Report Introduction This report will explain in short the history of Wireless Local Area Network (WLAN) and were it is usable. The standards that are there in for WLAN will help in clearly positioning the products for our use and evaluate them for the purpose that we have in our minds. WLAN is particularly useful in all those places where cabling is either difficult to make or is impossible to make. Or in all those places where mobile computing is what is required and not one single user might be on the network. In all these cases, wireless LAN becomes the best choice for usage. This report presents a clear comparison between the products that are available and the kind of usage that is possible with them. While some of the standards are stable and are usable in multiple environments, it is not the same with equipments that comply to a different standard. The report also presents advantages - disadvantages map between the standards that are existing and the reason why there is so many. We have also listed the security issues that plague the usage of WLANs. Status of Wireless LAN technologies Wireless LAN was and continues to be sought after because of some of the problems that are faced by LAN administrators and the users1. Typically the problems faced are: 1. Users are mobile and do not have network points available where ever they go. Particularly in public places like the airport, the hotels, etc., where these are created as hotspots. 2. Connectivity with out the hassle of laying out network cabling. Immediate availability of the network without any major time delay. Most of the Wireless LAN devices work under IEEE (Institution of Electrical and Electronics Engineers) standards. All the standardization started with 802.11 standards released by IEEE. Wireless LAN uses the radio waves for transmitting data from one to the other. It uses different frequencies for transmitting and receiving. The 802.11 laid down the rules for the communication protocol and specified which of the layers in OSI (Open System Interconnection model)23 are modifiable in case of WLAN. This paved way for changes in specific layers in OSI namely, the physical and the data link layers. In the initial stages of the development, the WLAN supported transmission at 2 MBPS (Mega Bits Per Sec) speed levels. When devices were built under this standard, they could maximum reach only these speeds. However new standards were introduced which goes up to 5.5 MBPS and 11 MBPS, in lieu of the original 1 and 2 MBPS that was achieved earlier. By 1999, it was amended and was expected to support 54 MBPS maximum and they were working at a clock rate of 5GHz. While the first set of standards was called only 802.11, the later ones came to be known as 802.11b and 802.11a. While 'a' is able to operate at a higher frequency, namely, 5 GHz (Giga Hertz), it is able to run it a higher speed than that of 'b'. WLAN implementations come up in multiple modes of operation. The equipments could be operating on a peer-to-peer mode or ad hoc mode. In this mode, the devices, could be PCs, communicate between them after recognizing each others presence. This is comfortable where one mobile unit has to communicate to another mobile unit over a WLAN. It is single, one-to-one and reasonably fast. No other needs be met under this methodology of operation. The second mode of operation is the common one, that through the Wireless Access Point. These access points connect multiple devices over the wireless network to a networked Ethernet connectivity. On one side the Access Point is a wireless switch and on the other it is Ethernet connectivity. This will help in connecting up like router or a switch multiple terminals to the Ethernet port. Access Points offer more than one technologies. Wi-Fi or Wireless Fidelity is one of the most commonly used wireless system in vogue. WiFi is a system that works with RF frequencies going up to 5.2Ghz. This means that we can have distances of up to 2 kilometers covered comfortably with WiFi systems. More than this, we will find WiFi not so efficient since it is bound to insert noise in the network. In order to circumvent this lacuna in the hardware, the access points are positioned at specific locations connected over a wired system. This will make those specific locations hotspots for wireless connectivity. The other methodology will be, use Access Points as if they are repeaters and transmit information across these repeaters to form a closed network. WiFi has been proving repeatedly that they could become the de facto standard of the industry as time rolls by. We also find other technologies such as Blue Tooth and Beamed transmission being employed pretty widely by various manufacturers and industries. The difference between the Blue Tooth and the wireless fidelity is that while blue tooth operates at a low frequency, the WiFi is at a high frequency. The cost of this low frequency is that it will not be able to carry the signal beyond 100 meters. Result: It can be used in applications that need connectivity within low ranges. In case beam, as its name indicates, this beams between two directed antennas of devices. This is a straight peer to peer connectivity and will carry messages from one system to another through a beamed RF way, necessarily from one device to another that is lying within the line of sight of the other device. Blue Tooth was originally made at Ericsson Labs for replacing cable in normal day to day communications like PC to Printer, audio system to head phones and other such short distance communications4. This was supposed to be a small cheap chip that will go into every one of the devices like the head phones, the audio systems, the PC, the printer and many others. This would therefore, can give a cheap and easy mode of communicating with these devices on a one on one basis, resulting in a totally wireless or cable less office that will work comfortably with the Blue Tooth technology adopted now. Now people have tried out communicating with printer to printer, printer to computer, mobile phones to printer and mobile phones to computer. All these and many more of them would all require such short distance but effective communication so that we need not make cables run between them. However the distance issue will remain as a problem for long distance communication work. Blue Tooth devices adopt IEEE 802.15.1 for low cost, short range Radio frequency connectivity between devices such us Personal Data Assistants(PDAs), mobile phones, printers, computers and any other such devices that are Blue Tooth enabled. They are made to this standard. This makes it possible to use any device that is compatible with blue tooth in conjunction with any other such Blue Tooth enabled devices. Such is the case with WiFi as well. Either of them are standardized and are used extensively. Significantly, Blue Tooth is also complaint with IEEE standards and propagates the same compliance scheme around. Wifi adopts to the IEEE 802.115 standards and the series of them, 802.11a, 802.11b and 802.11g. All these are standards for wireless communications between equipments. WiFi is a registered trademark of a trading group which makes WiFi compatible equipments. All new manufacturers who make such devices become members of this group. However, now, WiFi is coming out of the branding that was originally done and becoming a common property. Advantages and Disadvantages Every one of the systems have their own advantages. It is widely believed that the operating frequencies of the WiFi could be much improved so that they could go up to are even beyond 20 Km. Let us now take a close look at what are the advantages and disadvantages of each one of the systems6: Wifi: S No Advantages Disadvantages 1 This supports long distances and covers wider areas. Starts at just 50m indoors to about 5km outdoors depending on the frequency of operation. This is particularly suited in cases of campus wide to room wide WLAN enabling. Since high powered transmissions and receiving is to be done, it is necessary to have antennas, devices to be installed. It is not a simple plug and play affair. 2 Since it employs high frequencies the chances of error in communication is very low7. The noise infiltration is also low. High frequencies interfere with the operation of other devices in the area concerned. It will introduce harmonics in medical equipment, measuring devices, airplane electronics and other such devices. 3 The electronics involved is very well known and proven technologies. Therefore the electronics made is very dependable and rugged. The circuitry used for these proven technologies are not fully standardized. This needs to be done so that equipments communicate and work efficiently with one another. 4 WiFi offers an higher level of security when compared to most of the other technologies8. This adopts to standards like IEEE 802.11g and WPA the wifi protected access. The most commonly used system is then that also gets broken down faster since most people know how it works, it is also possible by most people to break it as well. 5 WiFi is found to be costlier than Blue Tooth in comparison. Blue Tooth9: S No Advantages Disadvantages 1 This does not support high power transmission systems, therefore, installations are just plug and play and easy. Low frequencies are used resulting in low distance transmissions. This will not support beyond 200 meters. 2 Since low frequencies are employed this is safe to be used in hospitals and other such locations. Since it employs low frequencies the chances of error in communication is relatively higher. That is the major cause for reduced distance in transmission. 3 The electronics involved is very well known and proven technologies. Therefore the electronics made is very dependable and rugged. The circuitry used for these proven technologies are not fully standardized. This needs to be done so that equipments communicate and work efficiently with one another. 4 Blue Tooth makes use of single chip that will enable transmission and receipt of data from a PC to a printer or audio device to head phones, etc., Therefore they are very cheap and are going down on their pricing more and more. Blue Tooth has the problem of clogging with more and more equipments being used in and around the same area. This is getting sorted out technically though of course it is yet to see the light of the day. 5 Blue Tooth is secure to a limited extent and is compatible to Wired Equivalent Protection (WEP)10. Beam and other similar technologies though they are under use are not widely employed and need not be considered at this point of time. Beam technology works on a line of sight methodology and works towards a solution based on per-to-peer communication. All these would be help us in deciding what kind of a wireless system do we require. Mobile Equipments Most of the mobile equipments come in one of these forms, either mobile phones or PDAs (Personal Digital Assistants) that also support telephony in them apart from the Laptops. Certain mobile phones today provide you with GPRS (General Packet Radio Service) which offer 24 hour connectivity as well. Let us take a closer look at the technologies supported by these mobile devices so that we can choose the right kind of an equipment in the company for their operation. Most of the Laptops under use today are WiFi enabled and work comfortably with the existing access points that are available in the market, mostly operating at a bandwidth of about 11 MBPS. Higher bandwidth products are also available up to 54 MBPS. However the limitation of the bandwidth is more a feature of the access point than that of the Laptop. Some of the laptops do come with Blue Tooth devices. It is also possible at a later date to have a plug in that enables the laptop to either be a blue tooth enabled one or the wifi enabled one. However, most of the PDAs and high end mobile phones come with an inbuilt blue tooth communication device as well as an in built wifi and beam devices. However, some of the PDAs support only one or two of them. Ideally we need to select the one that enables the WiFi support since that could be the one that is best suited for our requirements. Since WiFi is available across the globe it is a technology that has been adopted for various purposes. Blue Tooth is also employed by a multiple number of people, however it may be noted that this is not as wide spread as in the case of wifi. Security of Wireless Devices Wireless devices by default do not offer a great security. However, they do offer certain physical connectivity restrictions which are do not allow people to get connected to the network unless they are authorized. By definition, the wireless being an Radio Frequency (RF) connectivity is open for any body in the neighbor hood to connect or sniff the data that is in the air. This makes it highly insecure. The IEEE 802.11b and 11g are two IEEE standards that most devices adhere to and they are dictating certain standardization terms on the security issue as well. Wired Equivalent Privacy (WEP) and Wi-Fi Protected Access (WPA) are both offer higher level of protection though there are similarities between these and the IEEE standards. Almost all the devices, under WiFi11 or Blue Tooth comply to these standards on security issues. Advantages of employing this technology There are distinct advantages for the people in the company, typically, the architects, engineers and quantity surveyors. 1. The mobile application enables these employees to log on to the net from wherever they are and collect needed information on the move. This enables swifter and faster work execution. 2. This will improve booking of a requirement for a project as and when it is observed or needed rather than go through a manual process followed by an online work which could consume substantially higher time increasing the lead time needed to procure a material. 3. The same way, while discussing with the client if the client should need specific changes in material or manpower usage or to add importance to a specific job and get it completed faster, then the action required can be taken up immediately from the client's location itself. This will speed up the service to the client resulting in better customer satisfaction. 4. The quantity surveyors in their specific job could assess the material requirements and enter online from the field instead of coming back and making an entry on a terminal. 5. For the architects and the for the management, mobile access could mean that the fund flow is visible to them where ever they are. Dues from the clients and the payments to be made to the vendors; both would be visible to the user who can initiate suitable action. All these activities would speed up the entire process giving gains in man hours utilized and reduce errors since it is being gathered at the place where it is happening. Our choice of Technology Since the company is involved in civil construction and is not a place where high technology electronic gadgets are used, we can safely use high frequency devices like wifi rather than using devices like Blue Tooth12. Obviously, our stress will mostly be on the accuracy of data and reliability of the connectivity rather than on the infringement of the noise in associated circuitry. Our requirement will also be for longer distance in transmission in certain locations and neither are these locations going to be on line of sight. There are also multiple number of people involved who will be making the access to the network13. This will mean we need to ensure possibility of connecting more than one person on the network using the WiFi. Taking all these points into consideration along with the points listed in the previous sections, we can safely come to a conclusion that WiFi is the best suited technology for our company on a larger installation base. The blue tooth technology can be employed for communication in between the devices where ever it might be required. This could be in case of printer to PC or printer to printer etc., Read More