Abstract
The advent of heterogeneous broadband wireless access networks (BWANs) has been to support the ever-increasing cellular networks' data requirements by increasing capacity, spectrum efficiency, and network coverage. The focus of this chapter is to discuss the implementation details (i.e., architecture and network components), issues associated with heterogeneous BWANs (i.e., handovers, network selection, and base station placement), and also the various resource allocation schemes (i.e., shared resource allocation in split handover and inter-RAT self-organizing networks) that can improve the performance of the system by maximizing the network capacity.
TopArchitecture
Heterogeneous network (het-net) architecture is a prominent low-cost approach where an operator can exploit the different BWANs to provide additional areal capacity gain, indoor coverage improvement, and improved quality of service (QoS) in the network, as per Yeh et al. (2011).
Key Terms in this Chapter
Self-Organizing Network (SON): SON is a technology that simplifies and speeds up the planning, management, configuration, healing and optimization of NGMN (Next Generation Mobile Networks) that comprises of several RATs deployed.
Shared Resource Allocation: Resource allocation technique wherein resources of multiple RATs are pooled together to improve capacity and QoS in a mobile network environment.
Mobility Robustness Optimization (MRO): It is an algorithmic optimization framework that automates the adjustment of handover threshold of each cell based on measurement quantities such as SS (signal strength) and SQ (signal quality).
Multi-Tier Handover: It is an intra-RAT handover technique where handover occurs between hierarchical tiers (macrocell, picocell, and femtocalls) of an infrastructural RAT deployment.
Differentiated QoS: It is an end-to-end, application-level, QoS-management technique that classifies application-traffic into multiple classes with different QoS parameters.
Effective Capacity: Effective capacity of a system is the maximum constant arrival rate that can be supported by the system at the link layer.
Broadband Wireless Access (BWA) Networks: BWA technologies provide broadband data access over wireless LAN (Local Area Network), 3G, MAN (Metropolitan Area Network).
Radio Access Technology (RAT): RAT is the underlying physical connection method for a radio based mobile communication network such as Bluetooth, Wi-Fi, 3G, 4G, and LTE.
Split Handover: Shared resource allocation technique for cell edge users in orthogonal frequency division multiple access (OFDMA) networks, where MSs maintain parallel connections with more than one BS.
Network Selection: Network selection is a process in which the user devices (while requesting for a new connection or during the handover process) select from the radio access networks (RANs) that belong to competing service providers having different latency, coverage area, and cost.