Wireless Communication: Applications and Limitations
Wireless Communications
INTRODUCTION
First of all, the meaning of wireless must be clearly identified: Wireless communications are the technology that uses any type of waves to substitute the use of cables and wires in order to create links (or a certain kind of connectivity) between different devices; such waves can be radio waves, infrared waves, or microwaves.
Even though many people think that wireless communication is a new form of technology, the truth is that many devices that already existed for many decades use wireless technology, in one way or another, to accomplish the tasks or to deliver the services that they were designed for. Such devices include radio and television transmission-reception devices, military communication devices and many more. Mostly, such technology was being utilised only by governments and large organisations.
The difference that appeared in the last few years is the one that involves computer systems and other related pieces of equipment and that which involves telephony and communications, which made it possible for individuals and small and medium organisations to have access to such technology and to be able to use it for specific and personalised uses.
WIRELESS COMMUNICATIONS
Today, wireless communications are growing steadily in almost all sectors, which include home and individual uses, organisational and governmental uses, and scientific and research institutional uses as well. This is evident in every aspect of connectivity that is present and that is available for each person of us; mobile phones (especially those classified as smart-phones) are the most wide-spread devices that utilise wireless communications for almost all the requirements that wireless technology provides; this includes wireless voice connections, data and messaging connections, and multimedia (audio and video) exchange links. For those devices to be able to accomplish that, they cover most of the types of frequencies that are available through the use of technologies such as infrared, Bluetooth, WiFi, GSM and much more.
Wireless Local Area Networks (WLANs) are the most significant technological advancement since the beginning of the computer (and the Internet) age. Such technology provides the possibility of active connectivity to companies, universities, schools, research institutions, and even entities of a far smaller nature. A growing number of homes is now applying WLANs because it can provide the users with the same kind of service without the need for cables.
Prasad and Ruggieri (2003) give more details about WLANs by stating that “WLAN systems are a technology that can provide very high data rate applications and individual links (e.g., in company campus areas, conference centers, airports) and represents an attractive way of setting up computers networks in environments where cable installation is expensive or not feasible. They represent the coming together of two of the fastest-growing segments of the computer industry: LANs and mobile computing, thus recalling the attention of equipment manufactures. This shows their high potential and justifies the big attention paid to WLAN by equipment manufacturers. Whereas in the early beginning of WLANs several proprietary products existed, nowadays they are mostly conform to the Institute of Electrical and Electronics Engineering (IEEE) 802.11b (also known as Wi-Fi) standard. It operates in the unlicenced 2.4-GHz band at 11 Mbps and it is currently extended to reach 20 Mbps.”
When talking about wireless computer connectivity, it must be stated that there are two methods in which it operates today. The first is the “Ad Hoc mode, or Independent Basic Service Set (IBSS). This is a peer-to-peer wireless network. This means that it does not have an access point controlling the conversation.” This method is usually used for small networks which consist of five or less users. Its point of access which “manages the conversions is gone and the clients send beacons to each other… These beacons contain a timer synchronization function (TSF) to ensure that the timing is correct. This function is usually handled in the access point.” The second method is “the Infrastructure mode, which is called Extended Basic Service Set (EBSS). This is the main type of wireless network. In an EBSS, an access point controls all traffic. Setting up a wireless network in this category requires a piece of networking equipment referred to as an access point. This access point is where the Ethernet data is converted into a wireless signal that is then transferred out through the access point’s antenna. To hear and understand this signal, a wireless network interface card is needed. This card has a small antenna inside it and can hear the wireless signal and transfer it to the computer” (Earle, 2006).
As is the case for what concerns wired computer networks, wireless networks are either Wide Area Networks (WAN) or Local Area Networks (LAN).
As for the wireless LANs, Vacca (2003) explains that “wireless data local-area networks (WiFi LANs) have surged in popularity. WiFi LANs provide network access only for approximately 300 ft around each access point, but provide for bandwidth up to 11 Mbps for the IEEE 802.11b protocol, and up to 100 Mbps for the emerging 802.11a protocol. Best of all, the technology is available now and affordable” and the author explains that their reduced cost of deployment, compared to that of the wired LANs, made them more attractive in what concerns the enlargement of corporate networks to other locations: “The wireless data LAN is a ‘nice and clean’ extension to an office’s wired LAN. Wireless data LANs are attractive to offices that want to enable workers to take laptops into a conference room. Wireless data has a place now” According to the author, “WiFi is especially popular in the manufacturing, distribution, and retail industries”
Liska (2003) explains that the main purpose of using wireless WAN technology is to enable the connection to the Internet and to allow the connection between different offices (of a certain company, for example) that are located in different geographical locations. The author states that “Wireless WANs have emerged as a low-cost alternative to a traditional method of Internet access. Wireless WAN connection can offer the same amount of bandwidth as a T1, at a fraction of the cost. Wireless connections are also being deployed in areas where cable and DSL access is not available.”
Another form of wireless networks is the Wireless Personal Area Network (WPAN). In this type, the infrastructure network is not required as there is no need for a central link (or main connection of reference) as the connection is created between specific small devices and users within a given location. The main basic idea behind personal area network is the possibility to inter-connect two or more user-devices within a space of small coverage (that is not more than 10m) where ad hoc communication takes place which is also called personal operating space (POS). “The network is aimed at interconnecting portable and mobile computing devices such as laptops, personal digital assistants (PDAs), peripherals, cellular phones, digital cameras, headsets, and other electronics devices” (Prasad and Ruggieri, 2003).
To give more details about this kind of wireless network, Vacca (2003) states that “the term ad hoc connectivity refers to both the ability for a device to assume either master or slave functionality and the ease in which devices may join or leave an existing network. The Bluetooth radio system has emerged as the first technology addressing WDPAN applications with its salient features of low power consumption, small package size, and low cost. Wireless data rates for Bluetooth devices are limited to 1 Mbps, although actual throughput is about half this data rate. A Bluetooth communication link also supports up to three voice channels with very limited or no additional bandwidth for bursty wireless data traffic.”
For what concerns the standards of wireless networking, we find that for many years the systems were dependant on manufacturers, and this created problems regarding the compatibility of different systems with one another; that is why many standards are now present for use with the wireless systems. “This made the industry push the IEEE to make some wireless standards and help facilitate the growth of wireless with common standards that allowed various manufacturer cards to work with various manufacturer wireless networks” The standards used today include the 802.11 standard which “was the first WLAN standard accepted by multiple vendors as a true industry standard,” Other standards are 802.11a, 802.11b, 802.11c, and the 802.11g which was approved by the IEEE in 2003. There are other standards such as “The 802.11i standard [which is] a security standard that can apply to other 802.11 standards” and there is the 802.11j which is “for use in Japan only” (Earle, 2006).
According to Pallato (2004), a unified 802.11n Wi-Fi will be widely used soon. The 802.11n “is based on a new radio technology called MIMO (multiple input/multiple output) that allows the transmission of up to 100M bps over a much wider range than the earlier versions.” This will certainly be a step in the right direction in attempting to unify all the wireless standards into one technology that can be accessible to everyone anywhere. But this unification is facing problems and delays: Reardon (2006) explains that “the new standard that will allow notebook users to connect to wireless access points at much faster speeds than is currently available [will be delayed].. The IEEE approved a draft version of the standard called 802.11n, after much controversy and infighting among chipmakers. A second draft was due for the standard by late fall of this year [2006], but now a new draft won’t likely be ready until January 2007. This could push back the final ratification of the standard until 2008… The delay in adopting a standard has been caused by the nearly 12,000 changes to the draft that have been submitted to the standards group”.
The future of the wireless communications technologies is promising; this is because more mobility and speed are the most required factors in what concerns inter-connectivity, they are certainly more desired than the wired options, especially that the cost and the security options are being improved constantly. “Though still an imperfect technology, wireless data LANs are, nonetheless, booming and remain at least one market segment that’s expected to achieve its anticipated growth rate. IDC forecasts worldwide wireless data LAN semiconductor revenue alone to grow at a 30 percent compound annual growth rate during the next 4 years. And, 68 percent of networking solution providers already deploy wireless data LANs and WANs” (Vacca, 2003).
As can be seen by now, wireless technologies are becoming more requested and more used by all sectors of users, from large organisations to schools to home and office users. The overwhelming success of the mobile phone devices (especially the smart-phones with the possibility to have Wi-Fi, Bluetooth, and Infrared links) will force the industry to grow faster and to provide the instruments and the hardware needed for its propagation for lower prices. One of the emerging realities of today is what is called ‘Wi-Fi covered towns’: The more hotspots (or Wi-Fi access points) there will be available in homes, offices, coffee shops, restaurants, and bookstores, the more the ‘covered city’ concept can be put to practice. And with the arrival of the $100-smarphone by the year 2008, more and more people will find themselves directly inside the wireless age. Some are already talking about providing the Wi-Fi service through traditional radio frequencies, and with that, what we were accustomed to in what concerns TV reception can be used for wireless connections to the internet, and through that to the entire world. According to Long (2006), “One of the latest WLAN technologies [and one of those that are expected to flourish within the next 5 years], MIMO, or multiple-input multiple-output, splits the connection workload [within a LAN] into multiple data streams for increased range and throughput. Another technology, OFDM, or orthogonal frequency division multiplexing, is a technique for transmitting large amounts of digital data over radio waves.”
The future of communications is already known: Every individual will be able to get connected to any group of users he/she chooses, will be connected to his work network on the move and at his home and even when he/she is on vacation with no PDA or laptop. This is why the future seems to be revolving around the WPANs. The Wireless network installation and application will be extremely cheap that continuing with wired networks will be totally unacceptable by all means.
APPLICATIONS
Even if the beginning of the wireless applications was focused on applications related to vertical markets such as retail, warehousing, and manufacturing, “current growth is being driven by other market segments. These include enterprise, small office/home office, telecommunications/Internet service provider (ISP) and the public access throughput compared to cellular mobiles networks are the lead drivers for wireless LAN deployment. Voice over IP (VoIP) is also expected to drive this technology in the future” (Smyth, 2004).
Vacca (2003) explains that an entire range of applications and services are either dependent on wireless technology or are to be deployed depending on it. The author mentions the service of Triangulation which can be (and is being) used to locate the position of a mobile device through measuring the distance from two or more known points. Another application is Assisted GPS for determining the exact geographic position of the device in use. One important service that is also mentioned is the High-Resolution Maps service. Another important application of wireless networks is the one given to rural areas and locations where no cable or wire related new technologies can reach, for this the wireless technology can be deployed through satellite. “A new breed of satellite technologies and services allows providers to bring high-speed, always-on, two-way access to the planet’s farthest reaches. For example, McLean, Virginia–based StarBand Communications (a joint venture of Israeli satellite powerhouse Gilat Satellite Networks, EchoStar Communications, and Microsoft) is the first company to launch two-way consumer service in the United States.”
The potentials for wireless applications are endless in virtually all sectors. Such applications can be used for workers and sales employees, for warehouse personnel who order parts, for accountants who generate invoices, and for transportations companies such as DHL and UPS. “New applications are appearing at an ever-increasing rate. Mobile workers, such as salespeople, field service technicians, and delivery people, are an obvious target for new wireless applications…. Wireless technology applications can arm these workers with tools and data access capabilities that were previously limited to desk-bound employees” (Hayes, 2003).
With wireless communications, data transfer (especially of larger files, such as those related to multimedia – audio and video – and huge reports and presentations) will become easier whenever the mobile devices become improved in order to utilise higher bandwidths and faster access possibilities. TV and video streaming to wireless devices has already started and the improvements will keep on appearing. There are no limits to the applications of wireless technology. We have already reached the technological know-how that enables us to realise almost all the desired wireless applications, and the cost of their deployment and use will drop until it becomes more common than anything else. Any innovation in the wireless technology camp will be profitable to the manufacturers and desired by the users, mobility is something that is becoming more essential for any organisation or individual that aims at success.
“Wireless Applications are in their Internet infancy and awaiting broader bandwidth. As this becomes available the scope for applications on a cost-per-view basis will increase. Of particular interest for the future are the attempts to commercialize WWW by offering software, which relies on the WWW’s free infrastructure to be viable, on pay-per-use basis” (Bidgoli, 2004).
PROBLEMS
As mentioned earlier, one of the most important problems facing the wireless technology today is the different standards used by different manufacturers, but this is a problem that is supposed to be resolved shortly.
The real important issue is security. Earle (2006) mentions some of the security related issues such as Analysis (“the viewing, recording, or eavesdropping of a signal that is not intended for the party who is performing the analysis”), Spoofing (“impersonating an authorized client, device, or user to gain access to a resource that is protected by some form of authentication or authorization”), Wireless Denial-of-Service (“achieved with small signal jammers”), and Malicious Code (which can be used to “infect and corrupt network devices”). These risks are present in both wireless computer networks and in mobile devices such as mobile phones and PDAs.
The major solutions for this are encryption and authentication solutions in various kinds and modalities. But still, the security issue is the most important reason for delay concerning the movement of all the applications and services toward the wireless realm.
Another problem is the bandwidth; most mobile devices need to be developed further in order to turn the experience of using them into one that is similar to desktop computers and wired LAN connected devices.
Works Cited
Prasad, R. and Ruggieri, M. (2003) Technology Trends in Wireless Communications. Boston, MA: Artech House Publishers.
Earle, A. E. (2006) Wireless Security Handbook. Boca Raton, FL: Auerbach Publications.
Liska, A. (2003) The Practice of Network Security: deployment strategies for production environments. Upper Saddle River, NJ: Pearson Education, Inc.
Vacca, J. R. (2003) Wireless Data Demystified. New York, NY: McGraw-HIll Companies, Inc.
Pallato, J. (2004) Unified 802.11n Wi-Fi Standard to Emerge in Mid-2006. eWeek.com.[Accessed 22nd January 2007]. Available from World Wide Web:
Reardon, M. (2006). New Wi-Fi standard delayed again. ZDNet Tech News. [Accessed 21st January 2007]. Available from World Wide Web:
Long, M. (2006) The Future of Wireless Networks. Newfactor.com. [Accessed 20th January 2007]. Available from World Wide Web:
Smyth, P. (2004) Mobile and Wireless Communications:: Key Technologies and Future Applications. London, UK: The Institution of Electrical Engineers.
Hayes, I. S. (2003) Just Enough Wireless Computing. Upper Saddler River, NJ: Pearson Education, Inc.
Bidgoli, H. (2004) The Internet Encyclopedia. Hoboken, NJ: John Wiley & Sons, Inc.
