دانلود رایگان مقاله سلولهای مجازی TD-LTE: معماری SDN برای مدیریت منابع الاستیک کاربر محور مولتی ENB

Abstract

This paper introduces mechanisms and algorithms for managing efficiently the resources of Time-Division Long Term Evolution (TD-LTE) networks in a flexible manner enabling (i) dynamic frame alternation at each evolved Node B (eNB) and (ii) forming virtual cells, which allow diverse resource utilization to users residing within regions that can utilize resources from multiple eNBs. Our approach leverages the benefits of Software Defined Network (SDN) paradigm for monitoring network resource utilization and allowing applications or services to request resources. The resources requested by the applications or services can be allocated on-demand by adjusting the Time Division Duplex (TDD) frames in different regions of the geographical area being considered. This can be accomplished by creating virtual cells in the overlapping regions that can customize service for the residing users. A simulation study has been carried out to elaborate the benefits of this approach and the performance enhancements in comparison with the conventional TD-LTE configurations are presented. The results indicate significant performance gains of around 30%–35% considering both UL/DL directions respectively. Keywords

5. Conclusion

This paper introduced an SDN-based network management ar- chitecture and control mechanisms to provide resource elasticity in a TD-LTE system. Such a resource management flexibility intro- duced by this proposal can enhance the UL/DL diversity in a RAN deployment increasing performance gains, while providing a key enabler for the network operators to support a broad range of OTT application and cloud services with a wide variety of UL/DL traf- fic demands. The proposed mechanism can address flexibly UL and DL traffic requirements in an autonomous manner addressing ef- fectively pseudo-congestion by forming virtual cells enabling users to utilize resource from multiple eNBs allowing customized frames that resolve pseudo-congestion. An algorithm to manage the net- work resource providing flexibility and enhanced user performance has been introduced at the SDN controller to assess congestion situations and provide resolution via virtual cell provision and by enforcing TD-LTE frame re-configuration at selected eNBs. The re- sults obtained via system level simulations show significant im- provements in the average users performance including both edge users that reside within the virtual cell region and inner cell ones, without compromising the overall system performance. Further re- search is envisioned toward extending the proposed SDN based mechanisms considering split bearers and towards dynamic ad- justments in the mobile backhaul provisioning resources for lower layer transport mechanisms.