Smartphones have become as important as a telecom network and service layer for delivering a consistent and optimum user experience. With mobile vendors stuffing in lots of features the architecture complexity increases for supporting various technologies, applications, features and spectrum bands. Any degradation in the quality of these design architecture directly impacts the way smartphones operate and the resultant user experience.
For example, a sub-optimal antenna design in a smartphone may result in poor reception quality, poor data throughput and frequent call drops.
In India, there are more than 14,000 different smartphones being connected to a telecom network. India’s top telecom operator Airtel and Viavi Solutions conducted a study based on measurement and analysis of 8,000 distinctive 4G and 3G smartphone performance in India (exactly in Delhi city) which are active on Airtel network.
Because different smartphones have different specifications and RF characteristic the companies looked to analyse specific device parameters to give comparisons of how this may be affecting the user experience. These parameters offer a benchmark for how smartphones can be compared and qualified. Thereby providing a mechanism for telecom operator to engage with mobile vendors to improve on newer smartphones.
Performance metrics used to analyse
- Received Signal Code Power (RSCP): High RSCP indicates good downlink coverage for 3G smartphones.
- The ratio of received chip energy to interference (EcIo): High EcIo indicates good downlink signal quality for 3G smartphones.
- UE Transmit Power (UE Tx Power): Higher UE transmits power must be used by the UE to overcome a poor uplink channel and excessive interference. Higher values cause more interference and will place more demands on the smartphone’s battery.
- Voice (circuit) switched drop rate (CS drop rate): Voice drops significantly impact the quality of experience for voice call users.
- 3G-2G Inter-RAT (IRAT) Handover (HO) attempt rate: When a 3G connection falls back to 2G it will impact the quality of experience for data users.
- Retransmission ratio: The ratio of data transmitted, including re-transmissions, to the amount of user data measures how successful the air interface is at carrying the traffic. As the ratio increases above one, it indicates that many retransmissions are taking place and capacity will be impacted.
- Reference Signal Received Power (RSRP): High RSRP indicates good downlink coverage for 4G smartphones.
- Reference Signal Received Quality (RSRQ): High RSRQ indicates good downlink signal quality for 4G smartphones based on the reference signal.
- Signal to Interference Ratio (SINR): oftheSINR is an uplink measure that affects the shared channels. High SINR leads to more throughput and better use of spectral resources.
- Channel Quality Index (CQI): Higher CQI indicates that more efficient use is being of the radio resources.
- 4G-3G Inter-RAT (IRAT) handover (HO) attempt rate: When a 4G connection falls back to 3G it can impact the quality of experience for data users.
- 4G-3G Inter-RAT (IRAT) handover (HO) fail rate: When a handover to 3G fails it can result in an interruption in service with associated impact on quality of experience.
Some key findings from the study
- In the study, there were 8,000 unique smartphone models on the 3G and 4G networks combined.
- Around 50 percent of the unique subscribers are using the 68 most popular smartphone models which represent fewer than 1 percent of the smartphone models in the study.
- 90 percent of the unique subscribers are using 610 smartphone models, which is less than 8 percent of the smartphone models in the study.
- Over 55 percent of the unique smartphones had unique subscribers in single digits.
- Seven of the 3G smartphones (among 53 smartphones supporting only 3G) were found to be below the qualification /certification criteria.
- 17 of the 4G-capable smartphones were found to fail the qualification criteria.
If you are interested in learning more about the study, head over to Viavi Solutions [link]. You can freely download the white paper on smartphone performance analysis.