# Optimizing the Quality of Service of Mobile Broadband Networks for a Dense Urban Environment
## 3 Experimental Design
### Relevant 4G LTE Performance Metrics
#### 3.2.5 Throughput  
Evaluated based on [PERSON]'s law as a function of SINR and bandwidth, the measure of how fast data is transmitted over all resource blocks that a user is assigned is known as the throughput. It is location sensitive, as a user closer to the base station has a higher chance of getting more than a device far from the station. In maximum scheduling, the scheduler in the station (eNodeB) reports using the channel quality indicator (CQI) to get information about the user's channel quality experience and uses this information to assign RB to the user terminals. The request for this information is usually sent by the user equipment (UE), as different equipment at the same location (or a similar distance away from the base station) can receive different resources due to the difference in the device used. In this study, the PCC PHY DL throughput and the PDCP DL throughput are recorded and analyzed.  
With a major difference being the link being measured, the PCC PHY DL throughput and the PDCP DL throughput are quite similar, and both measure the rates of data delivery. While the PCC PHY DL throughput measures a physical link for the rate of successful data delivery in a 4G LTE network, the PDCP DL throughput is measured over a logical link. Although both measurements are in bits per second (bps), their purpose is different, as PCC PHY DL throughput presents a contextual mapping of the exact speed at which data is successfully delivered, while the PDCP DL throughput ensures, through a variety of protocols, that the data is properly transmitted by compressing and decompressing data, and sorting and interpreting the data transmitted.  
It is widely believed that the throughput is sufficient to evaluate the network performance of an MNO [1]. Also known as data rate, the throughput of a network can efficiently evaluate the performance of two different user devices or MNOs in a test area. Greater bandwidth from an MNO can also result in higher data rates leading to a smoother user experience. Due to its level of relevance, many works in wireless network technologies use the throughput (data rate) as a major KPI. This wide adoption of the throughput is seen in [41; 42].  
Generally, the throughput is determined using Equation (5)  
\[T=\frac{L}{S} \tag{5}\]  
where  
\(T=\) throughput,  
\(L=\) slot time measure of payload information transmitted  
\(S=\) slot time length.  
Equally important are the cell and user throughput denoted by \(T_{cell}\) and \(T_{user}\); they describe the data rates available per cell and user, respectively. While they describe similar concepts for the cell and the user, they depend on widely different factors. These dependencies are represented in Equations (6) and (7) for the cell and user throughput, respectively.  
\[T_{cell}=\frac{\sum_{0}^{15}S}{0.002\times(N+N_{i})} \tag{6}\]  
\[T_{user}=\frac{\sum_{0}^{15}S}{0.002\times\sum_{0}^{15}N_{buff}} \tag{7}\]  
where  
\(T_{cell}=\) cell throughput  
\(T_{user}=\) user throughput  
\(S=\) sum of acknowledged data scheduled every 2 ms.  
\(N=\) sub frames obtained every 2 ms.  
\(N_{i}\) = all subframes without pending user data.  
\(N_{buff}\) = user buffers scheduled for every 2 ms sub \(-\) frame.