Wireless Devices, Research Paper Example

The history of wireless technology that came to change our world so drastically started with the detection of radio waves – the discovery made by Heinrich Hertz in 1887. The scientist did not attach much importance to the phenomenon and it was only his followers Gugleilmo Marconi, Nikola Tesla, Reginald Fessenden and others who showed that radio waves were a power for remote control of objects and even for broadcasting voice. In more than a century of development wireless devices have reached amazing complexity and diversity and brought about dramatic changes to business world and private communication, medicine and armed forces, politics and science. They have enabled communication at places where there are no cords or cables, which hugely expanded our abilities, but they have deprived us from much of our privacy and security and made our lives more stressful. Cell phones make us both permanently available for phone calls and detectable in terms of our location and even habits.

Wireless Networking Devices

Wireless Routers & Print Servers

Wireless routers date back to 1999 when standards IEEE 802.11a (5 GHz frequency and 54 Mbps of maximum data rate) and 802.11b (2.4 GHz frequency and 11 Mbps of maximum data rate) appeared. The first wireless routers worked according to them. Not only did the new devices develop impressively within the following decade but they also made an introduction to the overwhelming majority of offices and households. The reason for their appeal is the absence of cords and mobility offered to multiple or single users. A great number of visitors can have internet access at your home or office due to a wireless router. A good example of business benefit can be numerous coffee houses which tend to attract visitors first and foremost with free internet connection and only then with a cup of coffee.

Wireless routers can use any broadband internet connection, be it fed from a cable or phone service provider. The router becomes an access point. A new LAN standard 802.11g of 2.4 GHz frequency was adopted in 2003. The standard functions of the transmission scheme of 802.11a, which enables the maximum speed of 54 Mbps. It was in 2009 that standard 802.11n sometimes called 11M or Wireless-N or even simply N was established. The standard allows the speed from 150 Mbps up to 300 Mbps. It should be mentioned, however, that maximum speed can only be achieved under certain conditions. With wireless routers, the speed is extremely vulnerable to the distance between the router and your computer as well as objects that might cause interference.

Wireless routers have become quite safe from any internet intrusions.  A user may choose to establish customizable firewalls or opt for a router that will only accept a single IP address. Special techniques are used to check individual packets and identify potentially hacker patterns. Media Access Control address filtering is another safety technique based on the identification of network devices. The system enables users to activate or refuse access. to the wireless router. Another option is the use of virtual private networks (VPNs) or VPN passthrough supported by many wireless routers.

Various encryption schemes are used to support further safety. Some of them are Wi-Fi Protected Setup (WPS), Wired Equivalent Privacy (WEP), Wi-Fi Protected Access (WPA). The most popular and effective today are WPS and WPA2. To allow internet connection for your visitors without dropping the security level, one may use Guest Networking feature present on many modern wireless routers.

A print server is a device widely used in office practice which allows to print out materials not only on the printer immediately connected to your computer with a wire but on any printer in the LAN. It usually has one LAN connector and physical ports attached to printers. The print server can either take the form of a separate server joined to other servers or be loaded on the existing server. The print server may even be a special hardware box (the examples include Intel Netport, Lexmark MarkNet, and HP JetDirect Ex). Finally, the print server such as the HP JetDirect Internal may be installed on the printer. After the installation of the necessary hardware, the software sets the number of printers and computer workstations to be joined by the print server. Having several printers in the network allows the choice of the most convenient one in terms of printing quality, accessibility etc.

The job of the print server is to convert the data sent from a client computer into the form comprehensible for a printer. The print server should therefore support a number of printing protocols such as LPD/LPR over TCP/IP, NetBIOS/NetBEUI over NBF, NetWare, TCP Port 9100 and RAW over TCP/IP, DLC and IPX/SPX.

Bluetooth

Bluetooth is a popular technology for communication at close range between a portable and/or fixed device. What Bluetooth means for users is reliable wireless connection at a low cost. As Bluetooth enabled devices get in the necessary radio proximity, they immediately create piconets, i.e. short-range radio networks. A single piconet can feed at the same time up to seven devices while each device can be included into seven different piconets, which means that Bluetooth devices can be linked in a great number of efficient combinations. According to the Core Specification, the term ‘short range’ implies a minimum of 10 meters, but the actual limit depends on manufacturers of particular devices.  The allowed range depends on the class of radio used in an application. Class 3 radio allows only a 1 meter piconet and class 2 enables 10 meter range (this one is most widely used in mobile applications), whereas class 1 covers 100 meters and is mainly used for industry requirements.

Bluetooth operates on ‘frequency-hopping spread spectrum’ radio technology. The data to be transmitted is divided into fragments of up to 79 bands of 1 MHz in the range 2402-2480 MHz. This band is popular in many countries as ‘industrial, scientific and medical band’ and unlicensed, which accounts for the quick spreading of Bluetooth technology and ensures it a secure market place all over the world.

Bluetooth wireless technology supports both data and voice transmissions and can therefore be used for voice calls, PC and mobile phones synchronizations, printing and faxing etc. Another reason for the wide appeal of Bluetooth technology is very low energy consumption. For instance, class 2 radio works on 2.5 mW and does not require energy supply while it remains inactive. Another feature contributing to energy efficiency is the Generic Alternate MAC/PHY which finds remote AMPs and only used the radio when transferring data.

Ericcson is responsible for the introduction of Bluetooth technology in 1994. The technology got its name from a famous Viking leader who united Denmark and Norway back in the 10^th century (the possible association is uniting various applications by means of Bluetooth). In 1998 Bluetooth SIG (Special Interest Group) emerged as an association of Ericcson, IBM, Nokia, Intel, and Toshiba to be further expanded with more than two thousand companies. Bluetooth reached a great number of consumers in 1999 with the introduction of hands-free mobile headset by Comdex. More than a million products featuring Bluetooth were shipped as early as 2003, says the Bluetooth SIG. The number rose to 700 million within five years according to In-Stat/MDR. In April 2009 Bluetooth SIG came up with the Bluetooth Core Specification Version 3.0 +HS enabling Generic Alternate MAC/PHY featuring increased speed. On July 6, 2010 Bluetooth Core Specification Version 4.0 with the emphasis on low energy consumption was established by the Bluetooth SIG. Unparalleled energy efficiency of Version 4.0 allows for Bluetooth to be installed on very small appliances working on coin-cell batteries and we can now expect Bluetooth enabled watches, toys, measuring instruments etc.

Infrared Technology Devices

Infrared wireless technology functions on electromagnetic radiation with a frequency range between 1 and 430 THz corresponding to the wavelength of 0.7 – 300 micrometers, i.e. on infrared light. These technical characteristics make infrared radiation a precious medium because it works beyond the radio spectrum. In fact, the radio spectrum is limited and therefore ardently competed for. For example, the valuable 700 MHz spectrum once served the needs of UHF TV but was taken from them to be sold by the Federal Communications Commission to such important players at the market as Google for several billions. The spectrum less than 300 GHz is regulated and radios that would work at this frequency are not cheap to build.

Fortunately, it is possible to break from the constraints to the frequency of approximately 300 THz which infrared radiation works at. It offers a great amount of unlicensed spectrum and almost unlimited geographical operation scope. Since infrared light cannot go through solid obstacles just like visible light, it can only operate effectively on the line of sight and exemplifies free space optical communication. Familiar examples of technology functioning on infrared radiation are TV remote controls, some wireless local area networks, and different point-to-point links. Interestingly, infrared radiation is included in the famous and widely used IEEE 802.11 standard (802.11 Infrared (IR) Physical Layer). The infrared part is responsible for 1 Mbps and 2 Mbps operation. The infrared right is reflected off ceilings, walls and objects to ensure connectivity on the premises. However, 802.11 IR tends not to be updated and to be lacking in later versions of the standard which fully rely on radio waves.

Another application of infrared radiation seems to be wider and more successful. It is the Infrared Data Association (IrDA) standard which a lot of appliances embedded in laptops and other portable devices operate on. Ironically, despite the great contribution IrDA protocols made in developments like Bluetooth technology, the tendency is for the IrDA appliances to be replaced by Bluetooth in laptops. IrDA is widely applied, however, in medical and measurement instrumentation, palmtop computers, and mobile phones.

It appears that the main factors stifling the development of infrared-based technology are the line-of-sight requirement and the fact that infrared wireless LANs do not conform with standards which means that both transducers and access points must be designed by the same manufacturer. Otherwise such LAN cannot be shared by many users.

Still, the Infrared Data Association finds a well-deserved place in modern technology such as a recently developed new LCD Controller enabling dual display on mobile devices by SHARP which is provided with an IrSimple interface for feedback from display to controller.

Cell Phones

Early Cell Phone History

It was as early as the 1940’s that the police first used radio technology for wireless communication between individuals. First cellular phones emerged in 1947 as off-springs of mobile car phones in Bell Laboratories. Martin Cooper, an electrical engineer from Chicago and the man behind the first portable police radio, headed Motorola’s research to produce the first cell phone in 1973. Only a decade later, in 1984, the public obtained access to cell phones. At that stage they weighted approximately four kilogram and cost up to $4,000. Dyna Tac 8oooX for $3,995 was succeeded in 1991 by Motorola MicroTac Lite for $1,000. The first cell phone that could be easily carried around was Motorola Micro TAC 9800X of 1989. All the previous versions failed to fit into a jacket pocket and were mainly confided to use in cars.

It should be mentioned that some parallel research took place. In the Soviet Union car-based radio mobile phones were designed by G. Shapiro and I. Zaharchenko as early as in 1946. Their achievement was followed in 1957 by the development of a portable mobile phone by L. Kupriyanovich in Moscow. The original device weighed about 3 kilogram but was in a year resized to a pocket version weighing only 500 grams. Östen Mäkitalo, a Swedish engineer, is sure to have farthered the Nordic Mobile Telephone system and arguably – the cellular phone as well. Overall, there is some confusion about the authorship of the revolutionary invention, so it might be more correct to talk about the international stream of scientific and technical thought which gave birth to cell phones in the early second half of the twentieth century as an inevitable fruit of knowledge of radio waves.

In 1968 the Federal Communications Commission enlarged the radio-spectrum  allocated for cell phone connection. Beforehand it used to be so limited that no more than 23 conversations could be carried out at the same time in a single service area. In cooperation with AT&T and Bell Towers, the Federal Communications Commission built the first broadcast towers, each with a hexagonal cell of only a few miles in radius. Despite the modest power of the first towers, the cells were overlapping, which enabled calls from tower to tower. Beforehand, one could only communicate by cell phone within the cell area, which naturally incurred inconveniences. One of the basic requirements the cellular systems had to live up to was ‘handoff’, i.e. the possibility to move from cell to cell without breaking connection. This was achieved by variable transmission power but the price of maintaining handoff in analog cellular systems was quite high.

The first nation to be covered by a 1G cellular network was the Japanese. In 1979 NTT launched the first network in Tokio and within half a decade the coverage was expanded nationwide. Scandinavia launched the second 1G network (the Nordic Mobile Telephone) which united Denmark, Finland, Norway, and Sweden. In the early 1980s the United Kingdom, Mexico and Canada followed with their 1G networks and the first one to be launched in the United States was Ameritech based in Chicago.

The 1990s saw the emergence of 2G mobile phone systems functioning mainly on GSM standard. The second generation broke from analog transmission to digital one was able to support fast phone to network signals. The innovations were responsible for the fact that mobile phones became truly popular – accessible and desirable for anyone and essential in a rapidly increasing number of spheres.  The popularity of mobile devices could not but be reflected in design requirements. The phones were getting smaller and smaller reaching the desired 100 – 200g standard. Naturally, it meant much smaller and more efficient batteries and smarter electronics. Another reason which helped the reduction in size was the growing number of cellular sites which required less transmission power in terminal devices.

The second generation offered an alternative to voice calls – text messaging which first appeared on GSM networks to win all digital networks later. While mobile running costs were still high for many, SMS text messages could be a good way to communicate the same but pay less than for calling. The application area of mobile phones was growing fast and by the late 1990s came to embrace money transfers copying the working principle of credit cards.

Current 3G Networks

If there is a dramatic difference between 1G and 2G networks and an obvious step forward from the former to the latter, defining 3G in comparison to 2G networks, which over years of development have reached quite sophisticated technical forms and most satisfactory levels of performance and won extensive coverage, might be more challenging. The next generation of mobile networks came as a response to the need for a global standard (and, consequently, a frequency band available worldwide) which would unite a great number of 2G networks working on national or even regional standards.

The response was formulated at the ITU World Radio Conference 230 MHz in 1992 as ‘Future Public Land Mobile Telecommunication Systems’ more widely recognized as International Mobile Telecommunications-2000 (IMT-2000). By this time 2G networks were so widespread and had cost so much that something revolutionary was likely to be met with little enthusiasm. One of the main features of 3G networks therefore was their obligatory backward compatibility within the working spectrum allocation. The revolution element existed, however, in the form of winning more spectrum, creating overlay network and using dual mode/band mobile applications. The ‘evolutionary’ standards comprise IMT –MC (cdma2000), which is an update on 2G CDMA IS-95 (cdmaOne), and IMT –SC (EDGE), an update on 2G TDMA (GSM/IS-136). The IS-41 core network allows IS-136 to be transformed into IMT-MC. The ‘revolutionary’ standards are IMT-DS (W-CDMA) functioning on 5 MHz channels, IMT-TC (TD-SCDMA/UTRA TDD), and IMT-FT (DECT). The last two require a TDD frequency assignment while the first works on wide channels, which means that more spectrum allocation is needed in comparison with 2G standards. IMT-DS, however, may count for ‘evolutionary’ in cases when the existing bandwidth would be sufficient.

The new standard was put into operation in 2000.

The third generation also meant increased performance norms such as data speed in the variety of working environments.

Current 4G Networks

Defining 4G technologies in comparison with 3G may be even more difficult since many of them are a development of 3G such as Long Term Evolution (an update on 3GPP claiming a 5 times greater spectral efficiency) or Ultra Mobile Broadband (an update on 3GPP2). Even the IEEE 802.16e (WiMax) standard, which is believed to be the core of 4G with its extensive coverage of areas with little infrastructure, was placed in the IMT-2000 family and thus associated with 3G. What the ITU really called ‘the fourth generation’ was IMT-Advanced, a collective name for advanced mobile capabilities. The ITU World Radio Conference of 2007 allocated the spectrum below 1GHz and above 2GHz for the benefit of IMT. In general, what 4G aims at in terms of channel bandwidth is the range between 5 and 20 MHz with a perspective of developing to 40 MHz.

We also need to mention IP Multimedia Subsystem Solution (IMS) standard which creates a ‘device, application and access aware’ network. As well as LTE, IMS is evolutionary and will provide both fixed and mobile operators with the necessary security and control at the stage of adopting the next generation architecture.

Understanding how precious the spectrum is, 4G researchers focused on new ways of packing information. The two techniques to achieve higher spectral efficiency that came as a feature of 4G era are Orthogonal Frequency Division Multiplexing (OFDM) and Multiple Input Multiple Output (MIMO) antenna technology. Both are included in LTE, UMB, and WiMax. MIMO is based on a system of algorithms designed to make the best of the mobile environment and support multi-megabit-per-second operation. Other basic techniques include channel-dependent scheduling, which allows to collect information about the condition of a particular channel and intensify or lessen the use of it accordingly, and link adaptation, which examines the quality of radio link and regulates modulation, coding and some parameters on the protocol.

The era of 4G is widely characterized by hyperconnectivity – the phenomenon of having a number of devices connected per user resulting in boosted penetration. Perfect handoff and global roaming with any two points connected at a minimum of 100 Mbit/s go for granted at this stage. The set speed norm is that of 100 Mbit/s for the client who is dynamic in relation to the station and 1 Gbit/s for a static client.

After almost seven years of preparation since the ITU declared the forthcoming advent of 4G era with IMT-Advanced family of standards in 2002, many clients could start enjoying 4G service provided, for instance, by Sprint in the United States (the service dubbed ‘4G’ not without reservations as download speed could hardly reach 10 Mbps) or by TeliaSonera (Norwegian NetCom) in Sweden and Finland.

Prospective 5G Networks

It might seem that 4G is not completely here and not allowed enough time to develop its potential, yet 5G prospects are already contemplated enthusiastically. 5G technologies are to comprise all the modern mobile features to provide users with unparalleled wireless experience of data exchange, storage and processing due to their unique data capability. The basic concept behind 5G is an attempt to break from the restrictions of Moore’s law and integrate most of existing wireless network technologies. 5G is to have ‘ubiquitous computing’ as its working principle, which will mean access to any applications based on any platform globally and at any time. The poetic name for the emerging worldwide system is ‘real wireless world’.

The global network is expected to not only expand communication capabilities but also bring about drastic changes to our daily practices. For example, your car equipped with sensors integrated in the 5G system will send an SMS text message to your cell phone if it senses intrusion. Home alarm and surveillance equipment with secured Internet connection will signal to you wherever you are in case of emergency. You will be able to pay the running costs of all your intelligent equipment in a single bill no matter what your network operator in every particular case is. Although the target is attractive, it is also rather challenging since it means developing global backward compatible standards that would work for all the previous versions. Nonetheless demanding is the requirement for a single platform which would interconnect the multitude of applications keeping them at the same time secure.

5G researchers aim at maximum upload and download speeds exceeding 1Gbps and 25 Mbps of connectivity speed

Our cell phones are already likely to compete with handheld computers in the range of functions they offer. One has to be an ascetic to still use the phone only to make voice calls, write text messages or set an alarm clock. Most users take MP3 players, cameras, video players, Bluetooth and Piconet technologies as part and parcel of a cell phone and the choice in cell phone design is staggering. What the fifth generation is going to offer is a global mobile phone allowing to call at any point on the planet as if one were calling the next door neighbor. Likely to render personal digital assistants completely obsolete for their lack of connectivity, mobile phones will store gross amount of information linked to any necessary appliances.

Modern Cell Phone Trends

If we are to name particular trends within the general tendency to use phones not only for calls, we would start with the feature which has already won the hearts of numerous users – Web browsing via a smartphone and accessing social networks. This is an area of growing competition between cell phones and PCs and, as nearly everyone might know from personal experience in terms of telephone services, cell phones are powerful rivals. Another trend is the introduction of qwerty keypads that were immediately taken to by bloggers, Internet surfers, journalists, language learners and just lovers of text messaging. On the contrary, those who do not enjoy keys can opt for a touchscreen. An important stream of innovations goes in the direction of providing greater security in emergency as well as any possible assistance to the disabled or senior. Children in different age groups are other target consumers for mobile phone manufacturers who strive to please children and at the same time put parents in control of their kid’s gadget. A cell phone may not be considered a strictly private thing, especially in developing societies. Family members or friends may choose to share a mobile and the tendency is so distinct that it makes cell phone manufacturers think of featuring multiple phonebooks and other possibilities for facilitating sharing. Growing integration between wireless technologies supports widely popular global positioning systems (GPS) and portable navigation devices (PND) which offer detailed maps and descriptions to both drivers and walkers. The concern of ecologists with the increased use and discharge of plastic enhanced by the spread of cell phones is being answered by the development of biodegradable cell phone cases.

Return on Investment

Keeping pace with the time undoubtedly means going mobile today. However, any businessman would calculate the potential revenue and weigh it against expenditure before establishing a wireless local area network. Even if the necessity of establishing a WLAN is out of question, one may consider the conditions such as leaving the access free or charging for it.

The first and easiest thing to count is the cost of wireless connection supply per month since it is obtainable from Internet subscription conditions. Analyzing customers’ readiness for paying for wireless LAN access may be more challenging and is likely to involve questioning via mail, email, phone etc. The answers will be more informative if questions contain some fee examples or expect customers to say how much they would be willing to pay. Another important factor to consider is how attractive your enterprise is going to be for customers in case it is provided with a wireless Internet access. The potential fluctuations of frequency of turning to the enterprise and length of staying with it are to be analyzed. If, for instance, it is obvious that the wireless Internet connection would attract more customers for substantially longer periods and the enterprise has the necessary capacity for it, the revenue not associated with customers’ paying for the Internet access is to increase and exceed the expenditure on the WLAN. In this case, it may be not reasonable to charge for the access. Statistical processing of the data obtained through surveys will show which scenario is to be opted for.

In the office environment, much depends on the size and geometry of the premises as well as the comparative cost and reliability of wired and wireless networks. If there are fixed places at desktops with radio wave obstacles between them in one’s office, a wireless LAN is unlikely to be a solution. However, if people prefer and have the possibility to move about the office with their laptops and need them, for example, at meetings, there is no alternative to going wireless and a more efficient office will contribute to a positive ROI.

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