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Wired radio communication:
The radio communication system consists of more radio base stations and in which are connected in serial manner, with at least one radio terminal. The more stations of radio base stations are communicated with the connected radio station with the help of radio. The radio network connection has capable to transmit information of radio channels by using all the radio based stations
Whereas the radio terminal try to connect radio channel, initially the first radio station in multi radio stations request the connection or required work of radio channel by the way of connecting wired control lines.
The connecting and retrieving the information means connecting only the vacant radio channel (which is not used by any radio stations and not connected by any of radio stations in multi channels. It is called as first radio base station process.
When the network connecting the wired communication line then it is called as the first wired communication line in multi communication system. When the first wired communication line moves from the first zone then the first wired communication line becomes second communication zone, it said to be a second radio station. So basically when first radio communication station moves to other zone automatically the second radio communication will occupy its zone place, it means the first radio communication is connected with second radio communication.
As per above statement the first and second radio communication system are connected by more than one, so it is called as multi or plurality wired communication channels. When it holds the data with each other then the controls are called as multi wired control lines, when individually sending the data by the system then is called as first and second radio base stations.
In this aspects at lest one radio base station should connect with other base station in multi base stations by the way of radio terminals via radio.
When the first wired line, wired communication , wired control lines and said wired communication lines connecting with radio base stations one by one and the information will relayed as per system receives first come first information basis. By this way the information will transfer one radio system to another radio system.
Radio communication and overlapping:
Radio communication is the process of transmitting the information signals by modulation of it in free space or medium. During this process the signals may overlap, when radio frequency is being set, the signal will be high at peak frequency and low at low frequency. The signal spectrum will not be at particular point either at high or low but it will be mostly at its mid frequency. The message signal bandwidth and spectrum width are related, to transmit the data, and decoder to receive it. Overlap will occur between two adjacent signals. The Access points are double tuners used in wireless communications that can receive or transmits the desired signals with same channel and same carrier frequency. The APs are made to access at a particular peak frequency to overcome overlapping, interfering, collisions of adjacent cells. Multiple APs are used to share the available channel so that mixing of signals in same channel can be avoided. The multiple APs will divide the channel into in to two non overlapping channels
Each AP will be selected at a particular range of a channel before transmission. Multiple APs will share with the available channel. The channels are reduced in order to avoid collisions. The divided APs are made to operate at peak state of the frequency. Wifi was designed to reduce the mixing of signals with less overlapping in wireless transmission. In the wireless LAN overlapping channel will reduce the collisions, interference, mixing of signals.
Operating the APs in peak frequency and mid frequency will arise a new problem.
SOLUTIONS FOR THIS NEW PROBLEM:
1. Study on the concept of overlapping by ‘Mitch Burton' tells us that, when signals are sent through same channel, the signal will not overlap or mix. Let us assume we have four wireless nodes as city, region, campus, in-building. The channel should be divided into two instead of one. Thus dividing the channels, interference of APs will be reduced to less than 4%-1% based on the number of divisions of the channels.
The current which is generated in wireless transmission uses filters which will reduce the APs interference. Time is slotted and the message signal must be sent at a particular time given to that signal in a particular channel. Thus we can say that by using two channels overlapping is reduced by selecting certain band width for each channel
2. The AP have a capability to assign necessary channels by default. This enterprise defined like boot process is a simple poll of every channel at randomized interval, the bunch of APs booting will not select same band. The basic algorithm will leads the results of channel assignment, picking channel is may be randomly or picking the old one which already used. Mostly all manufacturers will try to use that sort of wireless management devices which control the group of APs and apart from other functions, mostly the manufacturers will prefer the group which will a combined of channel and transmission power . This type of systems observed by the spectrum, this will leads to new interference sources or AP failures.
WAG's Advice on overlap:
The WAG(wireless Access Group) will suggest to set any of the AP's level or wireless by automatically using the channel at prescribed options. By using this process we can avoid the interference on booting initially better than the expected and satisfied level. The implemented wireless management devices can do the best job at a desired programmed. But it should produce required pattern by using less output power.
This shows that it needs more number of APs to cover an area or specified place with manually -assigned spectrum management.
This shows that the operators should understand well about the manually -assigned spectrum device.
The delicate analysis and effects of new methods, a wireless environment with procedured enhancing are latest and essential techniques for the interference. The area should be observed with
In WiFi position we must use two instead of one non overlapping channel so that the collisions will reduce with adjacent cells to a greater extent.
There will be another expected problem if two channels are also not enough, they are:
* When message moving through many building floors.
* When use of more than one channel, the other channels may mix.
* When passing message with unknown place.
During the above process there will be little overlapping in channels and hence collision of adjacent cells is also low. But the channel separation must be made correctly otherwise the total message will not reach the receiver end. The APs output power must be less in order to reduce collision of adjacent cells, and before Sending a message one should estimate what happens when overlapping become more. Then the channels must be divided to avoid overlapping. When we want to add another AP in the already existing design one had to redraw the total design with APs distribution in the area to get high expected output. But instead of the above procedure when one introduce another AP in the existing design by reducing the bandwidth of the spectrum, this may cause to overlapping of channels The institutions must make the spectrum management plan in wireless transmission in such away that it should be able to manage the channels to work effectively. The design must have:
1. further problems of overlapping channels will be solved by ‘official' WiFi services.
2. for the purpose of developing relationship with near networks will be done only with deploy wireless. (alternatively, try to get your kit deployed first)
3. the ISM band will rectify the unwanted or not related technologies which are used in system but it not necessary to limit our wireless networking options. This is for security systems purpose.
4. the police of radio communication on campus will be rectify only by developing policies of networking and observing the regimes.
TCP on radio communication and overlap:
The Transmission Control Protocol (TCP) is one of the important Protocol of the two protocols. The other protocol is Internet Protocol (IP), the two protocols combined together as TCP/IP. In which the TCP will work at high level transmissions. TCP can send a group of bytes from one computer program to another computer program it includes sending of mails with attached files. Besides this the TCP can manage the percentage of messages are transferred, where as IP can transmit low level transmissions i.e., it can transfer messages from one computer to another computer through the internet.
“In May, 1974, the Institute of Electrical and Electronic Engineers (IEEE) published a paper entitled "A Protocol for Packet Network Interconnection." The paper's authors, Vint Cerf and Bob Kahn, described an internetworking protocol for sharing resources using packet-switching among the nodes. A central control component of this model was the Transmission Control Program that incorporated both connection-oriented links and datagram services between hosts. The monolithic Transmission Control Program was later divided into a modular architecture consisting of the Transmission Control Protocol at the connection-oriented layer and the Internet Protocol at the internetworking (datagram) layer. The model became known informally as TCP/IP, although formally it was henceforth called the Internet Protocol Suite.”
TCP segment structure
The TCP segment contains TCP header and data section. The TCP header contains 10 main fields and one more extra field that be used based on the modifications. After the header segment the data segment will be there. In data segment the data will be transferred for prescribed purpose.
Options (if Data Offset > 5)
* Source port (16 bits) - identifies the sending port
* Destination port (16 bits) - identifies the receiving port
* Sequence number (32 bits) - has a dual role Connection establishment
TCP will provide the connection based on three-way or three-step procedure. Basically the user want to open the server for other connections, it must be merged to the port. And this is called passive opening. After the passive open connection now the user will start active open connection and this is done by three-way or three-step procedure:
1. The active open is done by user by sending SYN to the server.
2. Now the server will respond by sending SYN-ACK.
3. Lastly the user will send ACK back to the server.
Few features to set TCP:
* The data must be transferred without errors.
* Removing pirate packets.
* Sending again the packets which are not find at receiver.
* The data must be transferred with serial manner.
* Congestion control
During the transmission of data there will be loss of packets. This problem can over come by using TCP, in which data is settled in a serial manner so that if there is any loss in packets while transferring data can be recognized easily. By this the lost data bytes can be resent.
TCP will send the data in serial manner and at receiver end it is received. After receiving the data bytes in serial manner it will send back serial bytes and next byte is expecting to receive. During the above if any data is missed that can be resend. .
The serial numbers will remove the pirate data bytes and it will retransmit the lost data bytes in an ordered-data transfer to get the exactness a checksum field is introduced. The TCP checksum is the dull check in the latest check levels. Data Link Layers with more error bit rate may need extra error correction/detection capability. The dull checksum is reduced little by using CRC or integrity check at layer 2, under TCP and IP. The 16-bit TCP checksum will not tells that is redundant. Which means the errors in data bytes in CRC- protected is same. whereas the end-to-end 16-bit TCP checksum can remove the errors and this is called as end-to-end principle.
TCP over wireless network
For wired networks TCP is the easiest method. In wireless transmission of data there will be loss of expected data bytes at the receiver end. Due to data loss the congestion window size is reduced, this is considered as the advanced alert. In wireless transmission the instant losses are mainly due to interference, overlapping, and other radio effects these are not taken as congestion. The congestion window size is reduced due to data loss of wireless. This sort of works will effect on radio link. But, latest research programme's are tried to solve the problems and unwanted effects. Basically the suggestions for this problems are end-to-end solution, link layer solutions like RLP in CDMA2000 other wise proxy based solutions are considered.
The processing power used for TCP which is used to construct hardware implementation is over come by using one way known as TCP Offload Engines(TOE). The only problem of TOE is it is difficult to integrate the computing system, which needs more changes in the operating system of the computer or device. There are no companies to make such computers expect only one company called Alacro itech.