Figure # 1 is an example of the various types of femtocell access which are defined by the 3GPP. The closed access provides the contracted services to users who are part of the CSG, providing some level of security and privacy when accessing the femtocell, further that all resources are available for femtocell users, guaranteeing certain level of QoS. However, the users who are not part of subscriber's group can not access the network, except for emergency calls. This type of access generates more interference, since nearby mobiles try to connect to the femtocell, but they will be blocked due the access method, so a large number of implicit signaling is generated in that area.
On the other hand, open access has a good advantage for the service provider because part of the traffic is diverted by femtocells, releasing in largely, the macrocell's load. However, this type of implementation provides an increasement in the handover because a UE who moves to an area where there are several deployed femtocells, it will perform handovers on each femtocell with better signal quality, thereby increasing signaling traffic. From this perspective, the hybrid method may have advantages, but the shared resources by each femtocell must be managed carefully in order to not degrade the quality of service for the users into the femtocell.
References
- D. Calin, H. Claussen, H. Uzunalioglu. On Femto Deployment Architectures and Macrocell Offloading Benefits in Joint Macro-Femto Deployments. Communications Magazine, IEEE, vol. 48, no. 1, pp. 26-32, 2010.
- Assen, Golaup;Mona, Mustapha;Leo, Boonchin Patanapogpibul, Femtocell Access Control Strategy in UMTS and LTE, 2009.
- G, de la Roche;A, Valcarce;D, Lopez-Perez;Jie, Zhang, Access control Mechanisms for Femtocells, 2010.
- http://www.femtoforum.org
- http://www.3gpp.org/
