Parameter Definition Formula Target VoLTE Session Setup Failure Ratio [%] The probability that the VoLTE terminal cannot setup a session. VoLTE Session Setup Failure Ratio = (unsuccessful VoLTE session setup attempt/ all VoLTE session setup attempt) X100% ≤ 2% Return to 4G Time (LTE Networks) Return to 4G/LTE time is the average time (in seconds) it takes for a 4G/LTE call to return to form a legacy (2G/3G) network after a call has ended 𝑅𝑒𝑡𝑢𝑟𝑛 𝑡𝑜 4𝐺/𝐿𝑇𝐸[𝑠] = 𝑡first System information block in LTE received − 𝑡call ≤5 seconds fall back time from active state disconnected ≤10 seconds fall back time from idle state 5. QUALITY OF SERVICE PARAMETER FOR INTERCONNECTION Every Telecommunications Operators shall meet the following Quality of Service standards set for any interconnected service in respect of each specified parameter measured by real calls on any interconnected route and shall submit a periodic report based on daily peak hour conditions. Table 5: Quality of Service Parameter for Interconnection Parameter Definition Formula Interconnection Route Utilization The percentage of provisioned interconnection route that is carrying traffic Interconnection Route Utilization= (Total Capacity in use/Capacity Provisioned) X100%  70% Mean Time To Repair (MTTR) Interconnection Route The duration from a reported interconnection fault to service on Route restoration Mean Time To Repair (MTTR) Interconnection Route=Time Service Restored-Time Fault Reported  1 hour Point of Interconnection (PoI) Congestion The ratio of calls failed over the POI (between two Telecommunications Operators) due to unavailability of free circuits to the total call requests for seizure of POI circuit. POI congestion = failed call requests over the POI due to unavailability of free circuits/ (total call requests for seizure of POI circuit)x100% < 0.5% Time-frame for activation of a new POI The time frame for activation of a new POI is the time duration permitted for commissioning of interconnect capacity or link after confirmation or acceptance of demand for interconnect capacity provisioning and commissioning Counted from the date of confirmation or acceptance of demand for POI connectivity  90 days 17 Target