Cognitive Radio Network and Channel Allocation Problem - Samples

Question: Discuss about the Cognitive Radio Network and Channel Allocation Problem. Answer: Introduction The cognitive radio can be considered as a wireless communication system in which a transceiver can intelligently detect which communication channel are in use and which are not in use. This can help in moving to a free channel avoiding the occupied one (Han, Dianati and Nekovee2016). The concept mainly optimizes the use of the radio frequency which is available while concern to interference which is related to others. Considering the basic form, the cognitive radio is a technology which is hybrid which involves software defined radio as applied to the spread spectrum communication. The possible function of the cognitive radio mainly includes the foremost ability to transceiver to determine the geographic location, identify and the user authorization, decrypt and encrypt signals, sense wireless neighbouring devices in the operation and the adjustment of the power output and the characteristics of the modulation. The main aim of the report is put emphasis on the channel allocation problem. Taking into account the concept of how to allocate a single Dynamic Channel Allocations channel among the users who are competitive. The problem which is related with the techniques is also taken into consideration and comparison between the fixed channel allocation and the dynamic channel allocation is put forward. Allocation scheme There are mainly two types of allocation process fixed channel allocation and Dynamic channel allocation. Fixed channel allocation This allocation technique can be done using the static multiplexing method which are FDM and TDM (Frequency / time division Multiplexing). The frequency division multiplexing is used in radio or TV broadcasting. Dynamic Channel Allocation on the other hand time division multiplexing is used in POTS (Plain old telephone system). Problem in Fixed channel allocation. The main problem factor which can be related to it is that ones a channel is allocated it would not change the channel during its full operation phase (Moisio 2016). The channel would be fully busy with the process and sometimes resources are needed in some point of time. The process has to wait in order to gain the resource in the meantime the channel would be occupied and no other process can be initiated through the channel (Akaiwa and Andoh 2017). Dynamic allocation The process of dynamic channel allocation is done using the concept of pure/slotted ALOHA protocol or the carrier sense multiple access (CSMA) PROTOCOL. It is very much efficient than the process of static channel allocation as it uses the free collision protocol and does not waste bandwidth (Khodashenas et al. 2016) Assumption for the Dynamic channel allocation Independent traffic: independent stations. Single channel: which is available for the communication. All the stations can receive on and transmit from. Each of the stations are very much equally capable. Observe collision: all the station is able to detect collision (Zhao eta l. 2016). Slotted time or continuous (for transmission) Carrier sense or no sense carrier: without the sense of the carrier stations can tell if the channel is in use or not before making a move to use the channel (Tomabechi et al. 2016) Problem in Dynamic channel allocation. In the process of dynamic channel allocation, a process is allocated in a channel randomly. A particular process may require specific bandwidth for its execution. In some cases, it is seen a process is allocated a specific channel and results in loss of bandwidth. This bandwidth can be used by another process which require that amount of bandwidth (Joseph, Borst and Reiman 2016). Comparison between FCA and DCA Evaluation Parameter FIXED CHANNEL ALLOCATION DYNAMIC CHANNEL ALLOCATION Hand off blocking rate High Low Call dropping probability More Less Interference minimize Not good Good Network traffic load Un balance Balance Utilization of resource Less More Change AI location Do not change during the call processing Dynamically changes Complexity Less More Flexibility Less More Ion cost implement Low High The average block rate which is related to the handoff of the fixed channel allocation scheme is relatively high when it is compared to the average rate of blocking which is related to dynamic channel allocation scheme. In fixed channel allocation a set of channel is permanently allocated to each of the cell with regards to the network. This leads to be channel which is fixed and which does not change during the process (Loo, Mauri and Ortiz 2016). In the dynamic channel allocation schemes, all the channels are kept in a central pool and rare assigned dynamically to the new cell as they arrive into the system, this change can be leaded dynamically. In the fixed channel allocation system, the distance which is related to the cell which is using the same channel is very much minimum reuse distance for that system. Improvement of the performance Parameter 1: Throughout of the system Parameter 2: Latency decrease Parameter 3: Connectivity of the network improves (Jiang et al. 2016). Conclusion In recent times, the technology of the wireless resource has received much of the attentions. As a result of which vast amount of innovations are taking place in the concept of resolving the concept for solving channel allocation problem. This report mainly deals with the fixed channel allocation and the dynamic channel allocation and comparison is produced in the prospective of both the technology. The fixed channel allocation scheme is very much simple to implement and use and does not involve channel utilization constraints. In the dynamic channel allocation scheme there is no pre assigned channel in the cell of the cellular network. References Akaiwa, Y. and Andoh, H., 2017. Channel segregation-a self-organized dynamic channel allocation method: application to TDMA/FDMA microcellular system. IEEE Journal on Selected Areas in Communications, 11(6), pp.949-954. Han, C., Dianati, M. and Nekovee, M., 2016. IEEE Wireless Communications and Networking Conference 2016. Jiang, D., Ying, X., Han, Y. and Lv, Z., 2016. Collaborative multi-hop routing in cognitive wireless networks. Wireless personal communications, 86(2), pp.901-923. Joseph, V., Borst, S. and Reiman, M.I., 2016. Optimal rate allocation for video streaming in wireless networks with user dynamics. IEEE/ACM Transactions on Networking (TON), 24(2), pp.820-835. Kari, H., Nokia Telecommunications Oy, 2016. Channel allocation method for a packet network. U.S. Patent 6,597,682. Khodashenas, P.S., Rivas-Moscoso, J.M., Siracusa, D., Pederzolli, F., Shariati, B., Klonidis, D., Salvadori, E. and Tomkos, I., 2016. Comparison of spectral and spatial super-channel allocation schemes for SDM networks. Journal of Lightwave Technology, 34(11), pp.2710-2716. Loo, J., Mauri, J.L. and Ortiz, J.H. eds., 2016. Mobile ad hoc networks: current status and future trends. CRC Press. Moisio, M., 2016. Channel allocation method in a cellular radio network. U.S. Patent Application 10/171,380. Tomabechi, A., Matsushita Electric Industrial Co., Ltd., 2016. Dynamic channel allocation method. U.S. Patent 5,260,944. Zhao, W., Nishiyama, H., Fadlullah, Z., Kato, N. and Hamaguchi, K., 2016. DAPA: Capacity optimization in wireless networks through a combined design of density of access points and partially overlapped channel allocation. IEEE Transactions on Vehicular Technology, 65(5), pp.3715-3722.