With growing concerns on the quality of service parameters, including call drop, call quality, and data throughput, Pakistan Telecommunication Authority (PTA) has decided to amend the cellular mobile network quality of service (QoS) regulations.
The proposed regulations would be called ‘cellular mobile network quality of service (QoS) regulations 2021.’
QoS refers to the ability of a network or service to satisfy the end-user and is primarily linked with the aspects of services that are directly experienced by the consumers.
With the increase of the subscriber base, customer dissatisfaction is increasing, and complaints against the network are also increasing. Growing concerns on various QoS parameters, especially call drop, call quality, and data throughput, have been observed recently, PTA added.
To ensure a level playing field, along with a competitive environment and subscriber satisfaction, performance measurement with a common standard regarding QoS is a must.
QoS parameters can be measured both from network monitoring terminals and field surveys through drive tests. With the adaptation of 3G and 4G technologies, it is about time to set some benchmarks/thresholds for Cellular Mobile Operators (CMOs), which they must comply with to ensure consumers’ satisfaction.
The purpose of this consultation paper is to seek stakeholders’ feedback before finalizing and notifying the cellular mobile network QoS regulations 2021, it added.
PTA has stated that the QoS regulations 2011 and subsequent amendment in 2012 have a scope and applicability to all cellular mobile communication service to identify the minimum quality of service standards and associated measurement.
However, with the award of Next Generation Mobile Services (NGMS) licensees, the regulations need to be amended per NGMS licenses and keeping in view the international best practices and ensuring the provision of best service quality to consumers of mobile services.
The existing regulations provide Key Performance Indicators (KPIs) and measurement procedures, which are primarily concerned with voice service and short messaging service (SMS).
The regulations have not defined any KPI for NGMS or mobile broadband service. The QoS KPIs in cellular mobile network QoS regulations 2011, of voice and SMS services amendments, are suggested in the existing QoS KPIs regarding its measurement procedure and threshold values, etc.
Network Accessibility: Percentage of time mobile device is reporting “no service” or “emergency” as served technology during the drive test duration]. “No service” or “emergency” is the period mobile services are neither available to an end customer nor display of the network indicator on the mobile equipment. The proposed threshold is > 99 percent.
Network Downtime: It shall be measured from the network management system (NMS) of the operator as an average of one month, either across all the outdoor sites deployed by the operator in the surveyed area and as well any other area, i.e., district, tehsil, etc., provided by the Authority.
The sites on which services are restricted on the directives of the Authority shall be excluded in the calculation of this KPI. Only those dates will be excluded for restricted sites which are mentioned in closure instructions. Network downtime will be calculated separately for 2G (GSM), 3G (UMTS/HSPA+, etc.), and 4G (LTE) sites located in the mentioned area.
Network Downtime is the ratio of Total Time Network was not available to the Total Time during which measurement is taken and the proposed threshold is < 1 percent.
Grade of Service: It is the percentage of all attempts to make a call that does not result in a connection to the dialed number. It can be calculated as: [total no. of unsuccessful calls attempts/total no. of attempts] x 100, and the threshold should be ≤ 1 percent.
Call Connection Time: Following amendments are suggested in this KPI based upon the ITU Recommendation ITU-T E.807 Recommendation 7.1.5 (i.e., target), which states that “Ninety-five percent of these connected calls should have a call set-up time less than 10 seconds. Thus, the call set-up time is determined at the 95 percentile of the calls connected.”
The benchmark value of Call Connection Time is suggested to be ≤ 7.5 Seconds (including CSFB time). Time duration should be measured between CM Service Request and Alerting message in case voice call is initiated from 2G and 3G. Time duration should be measured between Extended Service Request and Alerting message for CSFB.
End-to-End Speech Quality: End-to-end service quality (mean opinion score) is represented by the average value of ITU-T P.863 ‘Perceptual objective listening quality prediction’ (POLQA) predicted MOS of all speech samples in successfully established calls.
Measurement will be based on the latest version of ITU- P.863 to achieve the correct relative service quality between VoLTE, HD-Voice, and legacy narrowband telephony.
Average MOS values shall be considered for each direction of communication for the duration of the testing for each designated area under testing. This KPI has to be achieved with 90 percent confidence based on the sample count in the surveyed area.
The award of NGMS licenses has paved the way for the introduction of new QoS KPIs for Voice and Mobile Broadband. The suggested QoS KPIs to be made part of the QoS Regulations are mentioned below.
PTA has proposed Call Setup Success Rate (CSSR), Call Drop Rate, RAB Setup Success Rate, and Inter System Handover for CS Voice for voice services of 2G, 3G, and 4G technologies.
For voice and data services of 2G, 3G, and 4G technologies, signal strength (Rx Level, RSCP & RSRP) has been proposed as KPIs. Furthermore, for 2G, 3G, and 4G voice and data services, signal strength quality (Rx-Qual, Ec/No & RSRQ) has been proposed.
For voice and data services of 3G and 4G technology sessions, an abnormal release rate has been proposed, and for data transfer, download/upload success ratio and user data throughput have been proposed.
For video streaming services of 3G and 4G technologies, video streaming success ratio, setup time, and MOS have been proposed. For browsing services of 3G and 4G technologies, webpage browsing success ratio and access time have been proposed.
For social media services of 3G and 4G, the social media success ratio and access time have been proposed. For data services of 3G and 4G, ping (latency, jitter, and packet loss) has been proposed, while for data services of 4G, E-RAB setup success rate has been proposed.