Wireless Access And The Transmission Bandwidth

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].

MIMO antenna configuration is requires in spatial multiplexing. In spatial multiplexing the high rate signal is divide into low rate signals and each individual stream is transmitted from different transmit antenna which is having the same frequency channel. Spatial multiplexing is technique which is capable of increasing channel capacity at higher signal to noise

Stations: A station (STA) is a network node that is equipped with a wireless network device. A personal computer with a wireless network adapter is known as a wireless client. Wireless clients can communicate directly with each other or through a wireless access point (AP). Wireless clients are mobile.

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.

Massive MIMO is an antenna technology for wireless communications in which antennas are used at both the

Obstacles like buildings and trees and even bad weather can also cause interference. To offset that, carriers will need to install more base stations to ensure better coverage, and use antenna technologies like MIMO (multiple-input and multiple-output).

There are lots of challenges occurs for reliable wireless communication which occurs due to physical limitations of the wireless medium. There has been massive growth occurs in wireless communication which is due to the techniques that improves spectral efficiency and mitigate various channel impairments such as fading and interference. Moreover there is always demand for high speed wireless internet and technologies which are capable of providing higher capacities and link reliabilities. Multiple-input-multiple-output (MIMO) is based on communication system which is able to fulfil these objectives. MIMO is an expansion of smart antennas systems. There were traditional smart antennas which occupy multiple antennas at receiver, whereas In MIMO system multiple antennas are engaged at both sides at transmitter as well as receiver side. The multiple antennas at the transmitter and the receiver side provide a major advantage over traditional smart antenna systems—in terms of capacity and diversity advantage. The multipath propagation by MIMO system is a remarkably advantage over other antennas system. Moreover it is able to provide independent fading channels between every pair of transmitter and receiver antennas.

This term paper is a comparison (difference) between two technologies which brought revolution in the field of mobile communication i.e GSM and CDMA . Firstly in the term paper , history of both of these technologies , GSM and CDMA is introduced along with their brief terminology . After the history construction , working and its application is discussed and compared . Finally the main difference in both the technologies i.e GSM and CDMA is summarized to complete the term paper .

A cell phone works as a series of non-invasive processes and actions. When a person dials a number on a handset, this number is converted into an electronic signal. This signal is then relayed to a base station. The base stations are also known as masts and they are the towers seen along road sides and atop buildings. From these towers, the electronic signal is transferred from one base station to another as it seeks a corresponding receiver in the form of another handset. When this signal matches, the phone rings and it can only be regarded as connected when the other party takes the call. This amazing technological advancement opened up new avenues in how we communicate. In the near future, a new process, “LTE, or 'Long Term Evolution,' is the new globally accepted 4G wireless standard. All of the U.S. carriers are turning it on” (PC Magazine).

TDMA uses timing to allow multiple signals within a specified amount of time. This would be like a large group taking turns talking at different time intervals. CDMA uses codes to allow multiple signals with specific individual codes. This would be like a group of individuals speaking in different languages. FDMA uses different frequencies within the signal. This would be like a group of individual speaking at different tones or levels. Using different code, time, frequency and other access schemes allows a large number of signals to be transmitted, identified and differentiated simultaneously.

* Set of techniques that allows the simultaneous transmission of multiple signals across a single link

At that moment, Marconi was about to produce detect radio waves from long distance. In 1896, the Wireless Telegraph and Signal Company Limited was established and became the first radio actor in the world. The first wireless signal was sent using Morse Code. Signals were received

The work has been able to verify that the number of mobile cellular network operators who can effectively share infrastructure on a base station is limited by the following parameters:

Finally, we give practical recommendations of how using the proposed combined LTE/MIMO Network with a Multi-beam antenna system will increase the system's capacity. This will allow the designers of wireless networks to obtain maximum data rate, better channel spectral efficiency and less bit error rate, and as a result, much better service and transmission performances.

According to A. Goldsmith (2005), wireless communications technology is asking as functions of mobile access. Since its inception, it has gone through several stages of development. Its wide range of applications to meet growing demand. (A. Goldsmith, 2005) Multipath fading