# Performance Model for Video Service in 5G Networks
## 1 Introduction
The static IC approaches include conventional fractional frequency reuse, which splits and distributes the spectrum among neighbor sectors [3; 4; 5]; partial frequency reuse, which splits the spectrum into two segments, one segment used for the cell edge user equipment (UEs) has a frequency reuse factor larger than one, and the other segment used for the cell center UEs has a frequency reuse factor of one [6; 7]; and soft frequency reuse, which splits the spectrum into N segments, one prioritized segment is used with higher transmit power for edge UEs, and other segments are used with lower transmit power for central UEs, and prioritized segments of neighbor cells are orthogonal in frequency [8; 9; 10; 11]. Dynamic IC approaches include IC approaches in frequency domain (FIC) and in time domain (TIC). Carrier aggregation-based IC [12; 13] is a dynamic FIC approach, which defines primary component carrier (PCC) and secondary component carrier (SCC): each cell allocates one PCC for call setup and control channel transmission, etc., and dynamically allocates SCCs, according to the traffic load, SCC selection algorithms are used to optimize the system throughput. The almost blank subframe approach is a dynamic TIC approach that allows time-sharing of the spectrum [14; 15; 16]. The cell causing interference mutes some subframes so that interfered cells can serve their UEs. These subframes are \"almost blank\" because broadcast signals are still transmitted over the subframes. For the above IC approaches, the sharing of time and frequency resources can be designed using graph- or utility-based approaches. The graph-based IC approaches (GIC) mitigates inter-cell interference by partitioning an interference graph, its nodes represent the UE and its edges represent the interference between UEs. The approach avoids the same time or frequency resources to be allocated to connected UEs to achieve a desired minimum signal-to-interference-plus-noise ratio (SINR) [17; 18; 19]. Utility-based IC (UIC) approaches maximize utility over the network [20; 21; 22; 23]. A two-level approach has been proposed in [21; 22; 23]: at the sector level, each sector calculates utilities for scenarios with a different number of interferers; at central level, a central unit allocates resources for sectors and resolves interferers' conflicts according to calculated utilities at the sector level. Millimeter-waves (mmWave) occupy the frequency spectrum between 30 GHz and 300 GHz, offer a solution for 5G networks because of the vast amounts of spectrum [24], and the small wavelength that enables the realization of massive MIMO antenna arrays in small sizes. By using massive MIMO antenna arrays, two IC approaches--coordinated beamforming (CBF) and coordinated multi-user MIMO (MU-MIMO)--were proposed. Precoding matrix indicator (PMI) coordination is a lightweight CBF approach, in which each UE transmits \"restriction PMI\" or \"recommendation PMI,\" and its neighboring base stations (BTS) can either avoid using the restriction PMI or use the recommendation PMI [25]. For coordinated MU-MIMO schemes, a virtual transmitter has been formed by nearby cellsto perform MU-MIMO transmission toward UEs, to eliminate inter-cell interference and achieve the highest cell capacity [26; 27]. Beamforming systems include switched beam systems (SBSs) and adaptive array systems (AASs). Switched beam system uses fixed beams and beam patterns to point to predetermined directions within a cell [28]. Adaptive array system forms a beam pattern for each user, the beam pattern is generated to direct the main lobe to the desired UE and nulls to interfered UEs for interference suppression [29]. The motivation for an SBS is its lower cost, as AAS is expensive for commercial mobile networks.