# Performance Model for Video Service in 5G Networks
## 3 Approaches
### Network Design Approach
Algorithm 5 shows the approach:
```
For service \(s\), UE number \(u\), beam number \(b\), and ISD isd,  Initial with design bandwidth: \(W_{0}\)  search database with (s, u, b, isd, Var(u), Var(s))  maxBW = max(BW(s, u, b, isd, Var(u), Var(s))  minBW = min(BW(s, u, b, isd, Var(u), Var(s))  Iteration = N;  Calculate QoS (s, u, b, isd, \(W_{0}\))  If TotalValidUE < UETHRESHOLD  While(true)  deltaW = (maxBW - minBW)/N; \(W_{0}+=\) deltaW  Calculate QoS (s, u, b, isd, \(W_{0}\))  If TotalValidUE > UETHRESHOLD  Break;  Add new \(W_{0}\) to database  EndIf  else  While(true)  deltaW = (maxBW - \(s\) minBW)/N; \(W_{0}-=\) deltaW  Calculate QoS (s, u, b, isd, \(W_{0}\))  If TotalValidUE < UETHRESHOLD  Break;  Roll back to previous \(W_{0}\)  End If  End For  End If  End For
```

**Algorithm 5** Network optimization

## 4 Simulation Methodology

The simulation network is a 19-cell cellular network using a hexagonal model. Each cell has 3 sectors and three directional antennas, one antenna points north, the other two are each deviated 120 degrees clockwise from the previous one. Out of the fifty-seven simulated sectors, seven cells in the center (21 sectors) were used to evaluate the performance. Each radio frame is 10 milliseconds, consisting of one hundred 0.1 millisecond time slots. The spectrum is split into resource blocks (RBs) of 900 KHz, each RB is split into 12 subcarriers. LTE TDD subframe configuration 2 with 0.75/0.25 downlink/uplink ratio, 64 quadrature amplitude modulation, \(2\times 2\) MIMO with closed loop spatial multiplexing transmission mode 4, control format indicator 1, and extended pedestrian A 5 Hz multipath model have been assumed. The max transmit power per sector is 47 dBm. Figure 5 shows the link curve based on above assumption from [23] assuming 10% of packet error rate. Four video services (S1: virtual reality, S2: interactive gaming, S3: conversational video, and S4: non-conversational video) were simulated, with different data rates and delay budgets (S1: data rate--25M, delay budget--20 ms; S2: data rate--5M, delay budget--100 ms; S3: data rate--5M, delay budget--300 ms). We assumed the same target packageloss rate of \(10^{-3}\). For S1 and S2, dedicated bandwidth is allocated for each service. For S3 and S4, shared bandwidth is allocated for both services, with the assumption that the traffic demands of the two services are 50% for each. The 3 GPP Urban Macro outdoor propagation loss model [31] has been used. Neglecting UE height, the line-of-sight (LOS) probability is calculated by:

\[P_{LOS}=\left\{ \begin{array}{ll}1&d_{2D}\leq 18m\\ \left[\frac{18}{d_{2D}}+\exp\left(-\frac{d_{2D}}{63}\right)\left(1-\frac{18}{d _{2D}}\right)\right]&18m<d_{2D}\end{array} \right.\]

where \(d_{2D}\) is distance between BTS and UE. Assuming less than 1 km of ISD, the path loss is:

\[ \begin{array}{ll}\par PL_{ULMA-LOS}=32.4+20 log_{10}(d_{2D})+20 log_{10}(f_{c} ),\\ PL_{ULMA-NLOS}=\max\left(PL_{ULMA-LOS},PL^{\prime}_{ULMA-NLOS}\right),\end{array}  \tag{16}\]

where \(f_{c}\) is carrier frequency of 28G Hz, \(PL^{\prime}_{ULMA-NLOS}\) is calculated by:

\[PL^{\prime}_{ULMA-NLOS}=13.54+39.08 log_{10}(d_{2D})+20 log_{10}(f_{c}). \tag{17}\]

The following describes how the simulation works: the 19 cells are placed according to hexagonal model, UEs are randomly placed in each sector. The network will be clustered according to Section 3.1.1, and the interference graph is built according to Section 3.1.2. At each time slot, the unscheduled UEs will be searched and each cluster will randomly pick one valid UE within its range (valid UEs means the UEs which have data in their transmission queue and have not be scheduled) to schedule, other valid UEs will be added according to intra-cluster interference coordination algorithm. After all clusters are scheduled, SINR will be calculated for all UEs according to the allocated beams and UE locations. If a UE has lower SINR than a pre-defined threshold, inter-cluster coordination algorithms will be run to un-schedule some of its interferers. Then, SINR will be re-calculated.