Chapter 1. Introduction. 1.1 Background. Wireless Communication

The main problem with the Wired in Mobility. Wireless technologies helps in overcoming the problem. The new wireless technology helps in establishing technology for the applications with low critical nature. Wireless communication offers flexibility and is inexpensive as we don’t use any physical cable like optical fiber, copper cable, co-axial cable, etc.. which are impractical as latency and reliability are not the major concerns. There are many types of wireless communication systems that can be categorized as Wireless LAN, Wireless PAN, near field communication. Short range

In Fig. 1, the 4 nodes are considered. Among the four nodes 2 of the nodes (Node 1 and Node 2) are primary networks and 2 other nodes (Node A and Node B) are secondary networks. The two networks act in different frequency range. The primary network acts at a range of 2.4GHz - 2.4835GHz range. The secondary network acts at a range of 433MHz - 473MHz represents the block diagram of the proposed system. The use of different frequencies increases the number of users. Node 1 and Node 2 communicate at 2.4GHz and Node A and Node B communicate at 433.9MHz. The nodes are made mobile and this causes high interference. This is cancelled by channeling where the frequencies are slotted. Multi-hop cognitive radio technique occurs when the data is transmitted from one secondary node to another which is out of range via primary node. At that time the primary node which is of MIMO antenna switches itself to the secondary node frequency and transmits the data. Wireless MIMO systems with multiple antennas employed at both the transmitter and receiver have gained attention because of their promising improvement in terms of performance and bandwidth efficiency [8].

In the recent years, wireless technologies have taken a new dimension in the ways society lives. Wireless broadband is available to everyone. Whether the users are at home, driving the car, sitting in the park, and it would even work while people are a pleasure boat ride in the middle of a lake. And because of this, the need to have information at any time and be connected in all places, all the time has been satisfied.

1. In your opinion, what is the purpose of our dropping the transmit power to such a low level?

The 10’s and 3’s rule are supposed to assist the network manager find the quantity of energy that is either received or lost in a wireless transmission. Different resources of RF interference may cause various stages of loss and gain. Therefore it is essential for one to understand the dB measurement to assist

The market for wireless communications has experienced incredible growth over recent years and wireless LANs have rapidly become a very

Shared bandwidth – all wireless devices compete for available bandwidth. As the number of wireless nodes increase, the bandwidth can be reduced, which decreases the performance of the network.

*** I was not sure what you were asking with this question, so I did the best that I could to answer this question. ***

IEEE802.11n made numerous changes to the 802.11 wireless standards that greatly increased the throughput as compared to earlier versions. 802.11n uses MIMO which is Multiple Input Multiple Output (also known as Multiple Antennas). MIMO makes use of multiple antennae to create multiple streams of communications between a transmitter and a receiver. The 802.11n amendment also introduced changes in the physical as well as MAC layers to make marked changes in the effectiveness of wireless networks. These changes included spatial-division multiplexing, space-time block coding, and transmitter beamforming.

Wireless networks are considered vulnerable when an incident occurs that exploits the capability to perform the desired requirement of maintaining performance and concealment of data. Most vulnerabilities happen because of the science behind a wireless network, the fact that it uses air as a medium makes it harder to protects because the environment of air is not stable and when it comes to delivering sacred information you must be on

Wireless networking hardware requires the use of underlying technology that deals with radio frequencies as well as data transmission. The most widely used standard is 802.11 produced by the Institute of Electrical and Electronic Engineers (IEEE). This is a standard defining all aspects of Radio Frequency Wireless networking

802.11ac is a fifth generation WLAN standard. The transfer speed of this standard is three times higher than the speed of its predecessor and is at the same time much faster than the standard that emerged in 1997. Its security is improved, and both the capacity and the range of this standard are significantly enlarged. Those features play a key role in its quality improvement. Its speed reaches up to 1Gbps, enabling high bandwidth transfer on multiple devices at the same time. The 5GHz channel reduces the number of errors. There is large number of wireless devices that broadcast equivalent omnidirectional signals but when using the 802.11ac standard there is an option to find the location of the broadcasting device in the network. Using this option, the sender can locate and send the packages directly to the device which is connected to the Internet and that is the reason why the signal is stronger, clearer and three times faster. The aim of this research would be to analyze all characteristics mentioned above and their practical implementation in a device that uses 802.11ac standard.

Although I have looked at Bluetooth, and some of its features, it is not a viable solution that we would be able to implement within our network design for Staffordshire Health Authority due to the types of devices we are using within the environment, they would be better supported using a wireless connection, other then point-to-point links offered by Bluetooth.

The IEEE 801.16 classified into two layers that are physical layer (PHY) and medium access control (MAC) layer. The PHY help four particulars which are single carrier (MAN-SC), Quadrature Amplitude Modulation (QAM), Time Division Duplexing (TDD) and orthogonal frequency division multiplexing (OFDM). WiMAX PHY is founded on orthogonal frequency division multiplexing to creating transmitter to achieve high speed data transfer. Physical layers are intended for non-line of sight operation in frequency bands lower 11 GHz.

Keywords— Orthogonal frequency division multiplexing (OFDM), Generalized K-fading, binary phase shift keying (BPSK), 16-qardature amplitude modulation (16-QAM), symbol error rate (SER).