Wireless Protocols
As with all data transmission technologies, protocols govern the manner in which information is transferred between stations. A protocol is simply an agreed upon standard that all parties use to ensure that different devices can communicate with each other. Wireless protocols can be discussed on their own, and where they fit in the OSI protocol suite. For the sake of clarity, we will limit our discussion to wireless network implementations.
Wireless protocols typically reside in layers 1 and 2, the application and presentation layers, respectively, of the OSI model. These two layers help direct how the data is gathered from the end station and prepared for transmission.
The main wireless protocol are: IEEE 802.11 covering wireless Ethernet; 802.15 dealing with wireless personal area networks (WPAN), including Bluetooth technology; and 802.16 for broadband wireless access.
802.11
The IEEE 802.11 specification family consists of four different, primary specifications:
• 802.11 – applies to wireless LANs and provides 1 or 2 Mbps transmission in the 2.4 GHz band using either frequency hopping spread spectrum (FHSS) or direct sequence spread spectrum (DSSS).
• 802.11a – an extension to 802.11 that applies to wireless LANs and provides up to 54 Mbps in the 5GHz band. 802.11a uses an orthogonal frequency division multiplexing encoding scheme rather than FHSS or DSSS.
• 802.11b (also referred to as 802.11 High Rate or Wi-Fi) – an extension to 802.11 that applies to wireless LANS and provides 11 Mbps transmission (with a fallback to 5.5, 2 and 1 Mbps) in the 2.4 GHz band. 802.11b uses only DSSS. 802.11b was a 1999 ratification to the original 802.11 standard, allowing wireless functionality comparable to Ethernet.
• 802.11g – applies to wireless LANs and provides 20+ Mbps in the 2.4 GHz band.
• 802.11n – applies to future standards for wireless data transmission that promises a maximum bandwidth of 108 Mbps through the use of multiple antennas (MIMO).
Strangely, the order of inception is not alphabetical. Rather, the specifications developed as follows: 802.11; 802.11b; 802.11a; 802,11g; and the projected 802.11n. The 802.11 family specifies the way in which wireless devices communicated with wired LAN base stations, or access points. Wireless-to-wired communication is known as infrastructure mode. A second mode, known as ad hoc mode, specifies the manner in which direct communication between wireless devices occurs.
Three of the four current specifications use the 2.4 GHz band. This is an unlicensed bandwidth, which means it is available free of charge to anyone with the technical to use it.
The 802 committee and the OSI model both relate to one another. The OSI model shows how the layers of the internet are able to communicate and function with each other. While the 802 committee will add onto that by showing how network protocols should function. With that being said there are numerous working groups under the 802 committee however the one that I will be writing about is the 802.2 or the logical link control (LLC). The logical link control is in the 2nd layer (data-link) of the OSI model. The purpose of this protocol is flow and error control along with multiplexing and demultiplexing. How multiplexing works is by getting multiple data streams and combining them into one shared stream. This is mainly seen in the common forms
Wireless networks – While the term wireless network may technically be used to refer to any type of network that is wireless, the term is most commonly used to refer to a telecommunications network whose interconnection between nodes is implemented without the use of wires, such as a computer network. Wireless telecommunication networks are generally implemented with some type of remote information transmission system that uses electromagnetic waves, such as radio waves, for the carrier and this implementation usually takes place at the physical level or “layer” network.
There was a time in our life when going wireless was a dream and was considered highly expensive but then started the era of WIFI. The first outcome of this wireless transmission was IEEE 802.11 standard for wireless data transmission and it progressed as a/b/n with the time. The last stand 802.11n was the real heavyweight and gained a lot of popularity based on its amazing performance. It gave almost 5 times increase in bandwidth using MIMO (Multiple Input Multiple Output) antenna technique. The user experience for 802.11n standard was so good that it was called “end of an Ethernet” at that time. AC standard operates in the 5GHz band with some enhanced physical layer set with the idea of better video communication. It comes with more antennas, wider channels and more spatial stream along with a number of new features to boost throughput and reliability. This new IEEE 802.11ac technology is in reality only an up gradation of physical layer wireless technique used in 802.11n by the use of multiple inputs multiple output (MIMO) antenna technique. Few improvements done in 802.11ac and modified parameters can be studied as following:
Generally speaking, typical scenario of communications networks interaction consists in a bunch of devices trying to communicate with each other by using the same medium. Home wireless networks, cellular networks, Ethernet environments are only a few examples of this setting.
Wi-Fi and WiMAX are corresponding. WiMAX networks usually provides a WiMAX subscriber unit which links to the metropolitan WiMAX network gives Wi-Fi located in homes or business for local devises for example Laptops, Wi-Fi Handsets and iPhones for connections (Xiao, 2008). This makes the users to put the WiMAX Subscriber Unit in the areas, which it can be received best and still are in a position to use WiMAX network for any place within the locality. WiMAX is more similar to Wi-Fi as compared to 3G cellular technologies. Wi-Fi provides local network access for a few feet with speed of about 54Mbpswhereas single WiMAX aerial haves a range of up to more than 40 miles with a speed of about 70Mbps or more than that. WiMAX brings an Internet connection that can serve the local Wi-Fi network.
Token ring LAN speeds of 4Mbps, 16Mbps, 100Mbps and 1Gbps have been standardized by the IEEE 802.5 working group.
L. Ophir "802.11 Over Coax - A Hybrid Coax - Wireless Home Network Using 802.11Technology", Consumer Communications and Networking Conference, pp.13 -18
... access to what and in which sequence. The router connects the LAN to other networks, which could be the Internet or another corporate network so that the LAN can exchange information with networks external to it. The most common LAN operating systems are Windows, Linux, and Novell. Each of these network operating systems supports TCP/IP as their default networking protocol. Ethernet is the dominant LAN standard at the physical network level, specifying the physical medium to carry signals between computers, access control rules, and a standardized set of bits used to carry data over the system. Originally, Ethernet supported a data transfer rate of 10 megabits per second (Mbps). Newer versions, such as Fast Ethernet and Gigabit Ethernet, support data transfer rates of 100 Mbps and 1 gigabits per second (Gbps), respectively, and are used in network backbones.
...This device allow data rate up to 100Mbps. It also Enclosure rating of IP67 for outdoor conditions.
WLAN (Wireless Local Area network) and its components: The task of developing a WLAN on commercial front possesses a greater challenge. Developing initial design, purchasing and installing components, managing and providing maintenance to the systems are the main basic parts of the WLAN. When we use WLAN on a commercial front then we may face the security and privacy concerns. The total area of that particular commercial area should be accessible. This is only possible with installing huge number of access points. The various components of the WLAN are
...n, M., & Grabianowski, E. (n.d.). HowStuffWorks "WiMAX Coverage and Speed". HowStuffWorks. Retrieved May 2, 2014, from http://computer.howstuffworks.com/wimax2.htm
Wi-Fi (Wireless Network) or 802.11 networking is a phenomenal way of providing Internet wirelessly at a low cost. Using radio waves, a wireless network connects a PC, mobile phone or just about anything that connects to the internet wirelessly by a router. By transmitting signals at 2.4 or 5 GHz it allows the waves to transmit more data at a faster rate. Typical Wi-Fi standards are 802.11a, b, g, n, or ac and they can switch up the frequency depending on the model (Brain). Families can create their own wireless network that can be shared between family members without the use of hooking all their devices up to the modem and can also protect their home network from potential hackers with the use of a TKIP or AES encryption. Businesses can also create a “hotspot” which is an area that has wireless networks for free or at a set fee. This is extremely convenient for commuters that need internet access while they are at work, waiting on a plane, or just sitting at a coffee spot without the need for wires(Cox).
The propose research will address a problem confronting many two year institutions in the present-day (i.e. how to best plan, design, and implement WLAN technologies). While WLAN technologies offer the benefits of mobility, reduced installation time, and decreased cost, many challenges must be met by institutions deploying them (Geier, 2005). These issues are related to security, speed, interoperability, and equipment selection, ease of use, reliability, signal interference, installation, and health risks.
Wu, H., Ramasubramanian, V., Gupta, a., Thompson, K., Culler, D., and Sun, J. A case for 802.11b. Journal of Wireless, Linear-Time Models 39 (Aug. 1996), 85-107.