دانلود رایگان مقاله مدل سازی عملکرد شبکه های وای فای نسل بعدی

Abstract

The industry is satisfying the increasing demand for wireless bandwidth by densely deploying a large number of access points which are centrally managed, e.g. enterprise WiFi networks deployed in university campuses, companies, airports etc. This “small cell” architecture is gaining traction in the cellular world as well, as witnessed by the direction in which 4G+ and 5G standardization is moving. Prior academic work in analyzing such large-scale wireless networks either uses oversimplified models for the physical layer, or ignores other important, real-world aspects of the problem, like MAC layer considerations, topology characteristics, and protocol overhead. On the other hand, for deployment purposes the industry is using on-site surveys and simulation tools which do not scale, cannot efficiently optimize the design of such a network, and do not explain why one design choice is better than another. In this paper we introduce an analytical model which combines the realism and practicality of industrial simulation tools with the ability to scale, analyze the effect of various design parameters, and optimize the performance of real-world deployments. The model takes into account all central system parameters, including channelization, power allocation, user scheduling, load balancing, MAC, advanced PHY techniques (single and multi user MIMO as well as cooperative transmission from multiple access points), topological characteristics and protocol overhead. The accuracy of the model is verified via extensive simulations and the model is used to study a wide range of real world scenarios, providing design guidelines on the effect of various design parameters on performance.

6. Conclusions

In this paper we have introduced an accurate and practical analytical model for next generation WiFi networks and applied it in a variety of real-world scenarios. An important result from this study is the significant performance gains that coordinated MU-MIMO has over non-coordinated approaches. That said, coordinated MUMIMO incurs additional overhead, and its gains are smaller in the presence of walls and other barriers which reduce inter-cell interference, as well as when considering a cap on the total number of APs that can be efficiently coordinated. Other interesting results are the sizable gains from sectorization, though to achieve those gains one needs to use front ends of varying complexity and cost, as well as how fast non-coordinated approaches become interference-limited resulting in no additional gains as more APs are deployed. As a final point, it is evident from the analysis of the various practical scenarios in this work that our model can be effectively used to guide the deployment of future wireless networks and optimize their performance.