Open, closed, and shared access femtocells in the downlink

Abstract

A fundamental choice in femtocell deployments is the set of users which are allowed to access each femtocell. Closed access restricts the set to specifically registered users, while open access allows any mobile subscriber to use any femtocell. Which one is preferable depends strongly on the distance between the macrocell base station (MBS) and femtocell. The main results of the this article are lemmas which provide expressions for the signal-to-interference-plus-to-noise ratio (SINR) distribution for various zones within a cell as a function of this MBS-femto distance. The average sum throughput (or any other SINR-based metric) of home users and cellular users under open and closed access can readily be determined from these expressions. We show that unlike in the uplink, the interests of home and cellular users are in conflict, with home users preferring closed access and cellular users preferring open access. The conflict is most pronounced for femtocells near the cell edge, when there are many cellular users and fewer femtocells. To mitigate this conflict, we propose a middle way which we term shared access in which femtocells allocate an adjustable number of time-slots between home and cellular users such that a specified minimum rate for each can be achieved. The optimal such sharing fraction is derived. Analysis shows that shared access achieves at least the overall throughput of open access while also satisfying rate requirements, while closed access fails for cellular users and open access fails for the home user.

Dynamic Channel Allocation in Closed-Access Small Cell Networks

“…워크를 가정할 경우 전력제어 [6][7][8][9][10] , 주파수채널 할당 [11][12][13][14] , 스펙트럼 센싱 [15,16] , 다중안테나 [17] 등을 이용하 는 방법이 제안되었다. 또한 개방형 접속방식을 이용 하여 앞에 제시된 방법 없이도 간단히 간섭전력을 감 소하는 방법이 제안되었다 [18] . [21] , 소형셀이 공존하는 경우 보다 진보된 형태의 방법이 연구되었다 [22,23] .…”

Auction‐based competition of hybrid small cells for dropped macrocell users

“…SCAs can be either operator deployed or user deployed. SCAs could operate in openaccess mode, hybrid mode or closed-group mode [2]. Among these three modes, works in [2] advocate for hybrid mode as it allows shared resources between host users (HUs) and guest users (GUs).…”

“…SCAs could operate in openaccess mode, hybrid mode or closed-group mode [2]. Among these three modes, works in [2] advocate for hybrid mode as it allows shared resources between host users (HUs) and guest users (GUs). The macrocell operator can provide incentives to the SCAs for serving its users [3,4].…”

A refunding strategy: opportunistic user association with congestion-based pricing in macro-femto hybrid network

“…Indeed, how to make each user access the appropriate network substantially affects the network performance [5]. Femtocell hybrid access is a promising choice to control user association between macrocells and femtocells [6,7], rather than the closed access and open access mode which render femtocells fully closed and open to macro users. Hybrid access permits macro users to exploit remaining femtocell resources after each femto user reserves its own capacity.…”