# mIoT Slice for 5G Systems: Design and Performance Evaluation
## 5 Performance Evaluations  
### Solution KPIs and Simulation Scenarios  
We perform a quantitative evaluation of our proposed 5G mIoT network slice, and compare its performance with a baseline 4G solution. The analysis has been focusing on the CP signaling and UP, taking the followings into consideration:  
* _total CP signaling_, measured in CP msg/s. It is the overall CP signaling in the CN given by the RAN-CN signaling (i.e., between eNodeB and MME in 4G networks and between the RAN and the AMF when considering 5 GS) plus the signaling within the CN (i.e., between the MME and the SGW/PGW in 4G networks and among the AMF, SMF and UPF in 5 GS).
* _bearer establishment_, measured in CP msg/s. It is the component of the CP signaling related to EPS/ACN bearer establishment that is triggered by the MME in 4G networks and by AMF for 5 GS.
* _bearer re-setup_ measured in CP msg/s (We are looking into a different method of bearer establishment and re-setup, as these messages could involve a different load for the CP entities.). It is the component of the CP signaling related to EPS/ACN re-setup, i.e., when an already existing bearer has been de-activated due to UP inactivity and needs to be activated again.
* _bearer update_, measured in CP msg/s. It is considered only for the 5 GS mIoT slice and it is the component of the CP signaling related to the update of an ACN bearer when a new PhD is added to an existing ACN bearer (i.e., Step 16 in Figure 3).  
Figure 3: Physical Device Registration and Aggregate Core Network (ACN) bearer Setup/Update. VD: Virtual Device; UP: User planes; CN: core network.  
* _UP resource utilization_, measured in UP pkt/bearer, i.e., the ratio between the UP traffic and the bearers enabled by the network to handle such traffic.  
The evaluation was performed using a software tool developed in Matlab simulation environment. An analogous network deployment for 4G and 5G systems has been considered, assuming that access nodes are connected to a single CN instance (a single MME, SGW/PGW for 4G, and a single AMF, SMF, UPF, PDN Gateway for 5G). In the developed software, devices perform a random access (RA) procedure [22] before transmitting their data. The random access procedure has been implemented by considering aspects such as power ramping, preamble collision as well as capacity limitation for random access response (RAR). RAN nodes have been configured as in [17] (macro-cellular coverage with ISD (inter site distance) = 1.732 km, 2 GHz carrier frequency, 5 MHz bandwidth, 54 preambles, RA periodicity set to 5 ms, 10 maximum RA attempts, and maximum six preambles addressed in a single RAR message). More details on simulation assumptions can be found in [17; 25]. The implemented simulation environment provides as outputs the CP signaling and the UP traffic generated from the random access procedure. The random access has been implemented by considering the signaling as discussed in [20] with the related parameters affecting the capacity of the cell and the latency in the generation of control and data messages (i.e., amount of time and frequency resources, parametrization of control and data channels, priority of data and control messages). In more details, the simulation environment models PRACH (Physical Random Access Channel), PDCCH (Physical Downlink Control Channel), PDSCH (Physical Downlink Shared Channel), and PUSCH (Physical Uplink Shared Channel) with the related RRC (Radio Resource Control) signaling generated between the UE and the base station and between the base station and the CN. The UP traffic is defined with packet size of 300  Bytes [26], while density and activation period (AP) of devices has been varied in our analysis. We considered a simulation interval of 1 h.