Introduction
The initial wireless networks were developed before the industrialization era. These systems transmitted information using rudimentary signals over a short distance. A highly structured set of signal combination was developed to pass across complex massages.
Observations stations were located on higher grounds and along the roads to convey these massages. These early communication networks were substituted originally by telegraph networks and later on by telephones. In the late 19th century, radio transmission was discovered and radio communication was invented.
Radio technology had a very limited capacity and this prompted the development of cellular systems. Therefore, wireless networks have undergone considerable evolution to its current state. Currently, wireless connectivity in use includes, infrared, cellular, and Wi-Fi, and the emerging ones such as 4G and blue tooth.
The promise of global wireless networks considerably increases the usefulness of the hand-held internet-capable devices (Goldsmith, 2005, p. 3; Akyildiz& Stuntebeck, 2006, p. 669; Sanchez & Daeyoung, 2008, p. 2).
Wireless communication has become the fastest growing sector of the telecommunication industry (Haykin & Moher, 2005, p. 8). As a result, it has captured the attention of the media and the minds of the general public.
The use of mobile wireless gadgets like the mobile phones has grown exponentially over the last decade and presently the number of users of these gadgets is estimated to be over 2 billion. As a matter of fact, cellular phones have become part of everyday life and a significant business tool, are swiftly displacing the old wireless systems in many countries.
In addition, wireless local area networks at present supplements or substitute wired networks at home, businesses, and learning institution. Numerous new applications, including wireless sensor networks, automated traffic systems, smart homes and machines, and remote telemedicine, are coming out from research ideas to tangible systems (Stallings, 2005, p. 6; Haykin & Moher, 2005, p. 9-10).
The volatile growth of wireless systems together with the proliferation of laptop and miniature computers points out a brighter future for wireless networks, both as independent systems and as part of the wider networking infrastructure.
However, numerous technological challenges remain in designing vigorous wireless networks that deliver essential to support new applications (Goldsmith, 2005, p. 4; Haykin & Moher, 2005, p. 8). This study aims at exploring the current wireless systems along with the emerging systems and standards.
The study will also discuss the wireless vision. The gap between the present and emerging systems and the vision of future wireless applications mean more work must be done to reach there.
Vision of Wireless Technology
Wireless technology aims at supporting information exchange between people or devices at the present and in the future. The vision targets multimedia communication around the globe using handheld devices or laptops. Wireless networks people from different locations including homes, offices, institutions, and recreational areas among others (Goldsmith, 2005, p. 5).
In the home wireless networks will enable a new category of intelligent electronic devices to work together and provide connectivity between cell phone, computers and security systems. These systems will also assists in monitoring disable, sick patients and the elderly at home. Wireless entertainment will pervade home and congregational places (Haykin & Moher, 2005, p. 11).
Wireless videos will ensure real time connectivity of global remote areas. Wireless vision also focuses military and commercial applications. Military applications include identification and tracking of enemy locations, detections biological and chemical weapons, support of automated vehicles and aircrafts, and counter terrorism (Akyildiz& Stuntebeck, 2006, p. 670).
Wireless applications include web browsing, internet access, voice messaging, paging, video teleconferencing, entertainment, subscriber information services among others. Wireless systems include cellular telephone systems, Wireless Local Area Networking Systems, Wireless Wide Area data systems and Satellite Systems.
These systems cover buildings, cities, regions and the globe (Stallings, 2005, p. 7). Wireless voice systems possess relatively low data rate requirements (approximately 20 Kbps) and can withstand a fairly high probability of bit error (bit error rate of around 10-3).
Alternatively, data systems generally require relatively higher rates (around 1-100 Mbps) and a very small bit error rates (about 10-8) with no fixed delay requirements. Wireless Real time video systems possess high data rate requirements combined with similar delay constraints as Wireless voice system. Paging systems have very low data rate requirement s and lacks delay constraints (Akyildiz& Stuntebeck, 2006, p. 677).
The different requirement of wireless systems has made it very hard to built one wireless system that satisfies all of the requirements. Wired networks generally integrate the different requirements of these systems using one protocol. This integration makes sure that majority of the strict requirements for all the applications are fulfilled at the same time.
While this may be possible in a number of wired networks, with data rate on the order of Gbps and bit error rates on the order of 10-12, it is impossible on wireless networks which have lower data rates and bit error rates. For these reasons, wireless vision aims at fragmenting wireless systems with diverse customized protocols to support the requirements of different applications (Goldsmith, 2005, p. 8).
The exponential growth of cellular phones and wireless internet access has brought a lot of hope in the wireless technology. However, experts warn that not all wireless applications will see the light of the day. While numerous wireless systems have enjoyed impressive success, there have also been numerous failures along the way.
As a matter of fact, it is very hard to predict wireless failures and successes to come. Furthermore, there must be adequate flexibility and ingenuity among the engineers and regulators to allow for unpredictable successes. It is apparent, however, that the present and emerging wireless systems together with the vision of applications will ensure a brighter future for wireless technology.
Benefits of Wireless Networks
The cost of purchasing the traditional wired infrastructure was very high and required a relatively longer time to install. These systems also involve additional costs and disruptions when relocating the offices. These costs depended on the quality of the infrastructure and physical layout (Haykin & Moher, 2005, p. 5).
On the other hand, wireless local area networks are cheaper and require less time to install (Stallings, 2005, p. 6). Most Wireless infrastructure are portable and requires no additional cost of installation incase the user is shifting hi/her office.
The wireless base stations can be placed anywhere and therefore can accommodate nearly an endless range of office configuration. Wired Local area networks consumes a lot of time and capital even from simple networks at home. With the traditional wired networks, each additional users or adjustments requires modification to the cabling system.
With wireless networks, employees of a given company can access company’s resources from any location within the transmission range. This flexibility and convenience enhances the productivity of the human resources. Wireless networks also extend the roaming benefits in all spheres of life.
For instance, procurement manager can easily manage logistics from the storehouse while moving about with their portable computers.
The total benefits of resulting from simplified implementation and maintenance coupled with roaming benefits helps to reduce and enhance organizational and human resource productivity. In addition, it minimizes total cost of ownership and of doing business (Haykin & Moher, 2005, p. 8; Stallings, 2005, p. 6).
Emerging Wireless Technologies
One of the most exceptional revolutions in the use of technology in the recent years has been the faster growth of wireless technology. Currently, wireless connectivity in use includes, infrared, cellular, and Wi-Fi, and the emerging ones such as 3G and blue tooth.
The promise of global wireless networks considerably increases the usefulness of the miniature internet-capable devices (Sanchez & Daeyoung, 2008, p. 2).
Infrared Wireless Networks
Infrared ports have been common among laptops and PDAs ([Personal digital Assistants) over the recent past. A number of printers and mobile phones also have infrared ports. The main use of infrared has been to provide communication channel between devices for synchronization, support, and transfer of files (Akyildiz& Stuntebeck, 2006, p. 678).
The speed of transfer is not as fast (4Mbps) as wired connections, even though nowadays some infrared ports can transfer data at the rate of 16Mbps (Sanchez & Daeyoung, 2008, p. 3). Infrared ports are also used to transfer information particularly contact information or calendar entries between mobile/ handheld devices.
This is very common in US and Japan where people exchange business cards and short messages through infrared (Akyildiz& Stuntebeck, 2006, p. 680). At the present, Utilities are available which allows for infrared interoperability among Windows/Pocket PC devices, Palms and even old Newton Message pads (Sanchez & Daeyoung, 2008, p. 4).
While infrared is the mother of wireless protocols, new applications keeps on being developed for its use. These include InfoPort, infrared financial messaging among others. InfoPort is an application for transferring large documents to Palm devices and is commonly used in institutions of higher learning especially in US.
Infrared financial messaging are new devices used in Supermarkets and large shops for standardization of payment. Business transactions, as a matter of fact, are considered as the future of infrared technology. This is because infrared networks are more secure and its device is placed next to one another.
What permits infrared communication among digital devices is a universal set of requirements developed by the Infrared Data Association (IrDA), originally published in 1994, and the most important of which is the Object Exchange Protocol (OBEX).
These specifications have even been used on new Bluetooth wireless protocols due to failure to come up with new specifications with each new technological advance. Infrared Data Association protocol has been built in the conventional operating systems such as Linux, Microsoft Windows and MacOS. IrDA Compatible ports are also added in other devices including Cameras, Scanners, and some printers.
IrDA Compatible ports allows Scanning of texts or images into a mobile scanner , which can then be beamed into laptop or handheld computers offering many possibilities for collecting such materials as realia for language learning or newspaper clippings (Sanchez & Daeyoung, 2008, p. 6; Akyildiz& Stuntebeck, 2006, p. 682).
Bluetooth Wireless Networks
Bluetooth was originally developed by Ericsson in 1994 and named after Herald Bluetooth, the Viking king who brought Norway and Denmark together. Bluetooth uses a shortwave, normally on radio signals that allows devices of all kinds to connect with each other.
Blue tooth devices include mobile phones, printers, scanners, computers among others. Since Bluetooth uses radio frequency waves, communication does not require a side by side connection of devices as Infrared.
Similar to infrared, Bluetooth is short range (usually ten meters), travels in all directions and can penetrate non-metallic obstacles. Long range versions capable of sending signals to over hundred meters, are still being developed (Stallings, 2005, p. 9).
Blue tooth transmits data at an optimal rate of 1Mbps. There has been a lot of speculation relating to Bluetooth and epoch of personal area networks of which this technology promises to build. The idea is that all domestic appliances will be embedded with Bluetooth device, all of which could be checked and controlled by Bluetooth.
Ericson envisages a situation in which small shoppers would access sales information through their mobile devices and send instantaneous pictures to their family members or friends. Many people view Bluetooth as a cable replacing technology, replacing wired serials and USB connections.
Contrary to Infrared, Bluetooth permits a point to multi-point connections, therefore creates for one particular occasion wireless connections of “master” and numerous “slaves”. In addition, Bluetooth communication can be kicked off by its own device, allowing for self-regulation and automated connections (Stallings, 2005, p. 9-10; Goldsmith, 2005, p. 23).
Wi-Fi Wireless Networks
Wi-Fi is widely viewed as a substitute for wired Ethernet. Wireless Local area networking (LAN) technology has been around for over three decades. Nevertheless, these networks worked at a low speed and were complex to use.
In the late 20th century, Institute of Electrical and Electronic Engineers (IEEE) came up with the 802.11 standard for wireless local area networks using non-licensed 2.4 GHZ frequency band in contrast to 900 GHZ used before. This standard was later revised to 802.11b, which increased transmission speed to 11Mbps from 2Mbps.
This standard is what is referred to as Wi-Fi (wireless fidelity) nowadays or wireless LAN. In contrast to Bluetooth, WI-Fi technology requires a base station or access point to connect with the clients who must also have PC card or adaptors tpo connects with the access point.
Similar to Bluetooth, WI-Fi can also travel through non-metallic objects, although they travel better through wooden objects or drywall than on concrete or stone walls. Wi-Fi transmission varies from 50 to 300 feet depending on the equipment used and design. The distance can be increased to over 20 miles by using high gain antennas (Sanchez & Daeyoung, 2008, p. 12).
Wi-Fi popularity rose in 1999 when Apple introduced its wireless networking technology. Apple incorporated Wi-Fi antennas into all of its potable computers and provided appealingly priced base stations able to communicate with up to 10 users.
The current version can accommodate up to 50 users. At the moment numerous Wi-Fi base stations are readily available in various electronic vending shops. As a result of its price reduction, wireless networks have grown considerably. The growth of wireless networks in homes has been driven by the increasing attractiveness of the advanced speed internet access through cable and Digital Subscriber Line (DSL) modems.
Wi-Fi base stations allows for multiple sharing of internet by users. Since Dynamic host configuration protocol (DHCP) is built into most of the Wi-Fi hub, all devices can use one IP number. The Wi-Fi access points can also be connected to traditional wired internet connection. Other base stations have integrated firewall support into their system (Sanchez & Daeyoung, 2008, p. 13).
Other Wireless Connections
North America and Europe has been travelling a different path when it comes to wireless local networks. U.S. and Canada have embraced 802.11 xs while Europe is leaning toward HiperLAN2.
This has resulted into undesirable state of affairs in cellular phones, with Europe and the rest of the world using Global Systems for Mobile Communications (GSM) while North America uses its own analogue (AMPS) and digital (CDMA) wireless systems. GSM is also available in U.S. and Canada but its coverage is far and beyond.
Their interest in GSM was due to worldwide compatibility and the fact that they wanted to introduce a successor to GSMD by the name GPRS (General Packet Radio Service. GPRS offers a high band width data internet access and data transmission.
Over the recent past, the mobile phone world has also been clouded by the 3G, the third generation cellular network. 3G combines high speed mobile access with IP-based services and has been claimed to be the future of internet access.
It is fast, dependable and always in connection. Its data transfer rate ranges from 144kbps to Mbps. 3G is based on a revised version of CODE Divisional Multiple Access (CDMA) known as Wideband –CDMA. Most telecommunications companies are currently spending billion of dollars to buy licenses so as to operate in 3G networks.
Currently a fourth generation wireless system otherwise known as 4G is being introduced and is much more superior to 3G (Akyildiz& Stuntebeck, 2006, p. 682; Sanchez & Daeyoung, 2008, p. 13).
Conclusion
One of the most exceptional revolutions in the use of technology in the recent years has been the faster growth of wireless technology. Wireless technology has evolved considerably from rudimentary systems which transmitted information using rudimentary signals over a short distance to the more advanced systems we have today.
The volatile growth of wireless systems together with the proliferation of laptop and miniature computers points out a brighter future for wireless networks, both as independent systems and as part of the wider networking infrastructure.
Over the recent past, the mobile phone world has also been clouded by the 3G, the third generation cellular network. 3G combines high speed mobile access with IP-based services and has been claimed to be the future of internet access.
It is fast, dependable and always in connection. Its data transfer rate ranges from 144kbps to Mbps. 3G is based on a revised version of CODE Divisional Multiple Access (CDMA) known as Wideband –CDMA. Most telecommunications companies are currently spending billion of dollars to buy licenses so as to operate in 3G networks.
Currently a fourth generation wireless system otherwise known as 4G is being introduced and is much more superior to 3G. However, experts warn that not all wireless applications will see the light of the day. While numerous wireless systems have enjoyed impressive success, there have also been numerous failures along the way.
As a matter of fact, it is very hard to predict wireless failures and successes to come. Furthermore, there must be adequate flexibility and ingenuity among the engineers and regulators to allow for unpredictable successes. It is apparent, however, that the present and emerging wireless systems together with the vision of applications will ensure a brighter future for wireless technology.
References
Akyildiz, I.F., & Stuntebeck, E.P. (2006). Wireless underground sensor networks: Research challenges. Ad Hoc Networks, 4, 669-686.
Goldsmith, A. (2005). Wireless Communications. New York: Cambridge University Press.
Haykin, S., & Moher, M. (2005). Modern Wireless Communications. Upper Saddle River, New Jersey: Prentice Hall.
Sanchez L.T., & Daeyoung, K. (2008). Wireless Sensor Networks and RFID integration for Context Aware Services. Technical Report, Auto-ID Labs White Paper, White Paper series 2008.
Stallings, W. (2005). Wireless Communication and Networks, 2nd Ed. Upper Saddle River, New Jersey: Prentice Hall.