Abstract
There are two main access policies (open and closed) to Femtocell Access Points (FAPs), being closed access the customers favorite. However, closed access is the root cause of crosstier interference in cochannel deployments of two-tier networks (i.e., macrocells and femtocells). Further, the effect of this problem is remarkably serious in the downlink of outdoor users not subscribed to any femtocell. Open access has been considered as a potential solution to this problem. However, this increases signaling in the network due to the elevated number of HandOvers (HOs) that mobile users have to perform. Therefore, this paper proposes an interference avoidance technique based on the use of Intracell HandOvers (IHOs) in Orthogonal Frequency Division Multiple Access (OFDMA) femtocells. It is shown that a proper combination of IHO and power control techniques reduces the outage probability for nonsubscribers compared with that of closed and open access. In addition, the impact of several network parameters such as the femtocell penetration is also considered in the analysis.
Highlights
Open access has been regarded [1] as a feasible solution to the problem of cross-tier interference in two-tier networks
When outdoor users are allowed to connect to any available cell it is likely that due to the nomadic nature of these users, their connections would be continuously transferred between adjacent femtocells, or between femtocells and the umbrella macrocell
Let us mention that the Intracell HandOvers (IHOs) threshold SINRIyHO has been set to 3 dB, which is a value slightly larger than that of the lowest Radio Access Bearers (RABs) defined in the system, that is, 2, 88 dB
Summary
Open access has been regarded [1] as a feasible solution to the problem of cross-tier interference in two-tier networks. Open access femtocell deployments are hardly practical due to the elevated number of required handovers. When outdoor users are allowed to connect to any available cell (i.e., macrocell or femtocell) it is likely that due to the nomadic nature of these users, their connections would be continuously transferred between adjacent femtocells, or between femtocells and the umbrella macrocell. It is well known [2] that HOs are not always successful and connections might be dropped as a consequence of HO failure.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
