Village Coverage Complaint, Weak RSRP and Evening Congestion
An operator's 4G site serves a village from a 30 m tower 2.8 km away. The sector antenna is downtilted 4° and its azimuth is aimed 30° east of the village centre. Field measurements at the village centre: RSRP −108 dBm outdoors, −117 dBm inside houses, SINR 2 dB, download 0.9 Mbps between 8 and 9 pm but 6 Mbps at 5 am. A second operator site 9 km away runs on the same band. The panchayat has collected 300 signatures demanding 'a signal booster in every house', and the local representative wants a solution within a month. New-site budget is limited and a new tower would need 8–10 months for approval and civil work. The RF team can re-aim and re-tilt the existing antenna within a week at negligible cost.
1. Interpret the RSRP, SINR and time-of-day throughput figures. How many distinct problems are present, and what does each measurement rule in or out?
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Three signals point to two separate problems.
- Coverage is weak. RSRP −108 dBm outdoors is poor (roughly: better than −90 good, −90 to −105 fair, below −110 poor). Indoors at −117 dBm the phone is close to losing service. The 30° azimuth offset from the village and 4° downtilt both push energy away from where the users are.
- Quality is poor, but probably as a consequence. SINR 2 dB is very low, yet with RSRP at −108 dBm the serving signal is weak, so low SINR is expected even without a dominant interferer. The 9 km co-channel site is a candidate interferer but cannot be confirmed from these figures alone; a scan or neighbour-cell report is needed.
- There is also congestion. Throughput falls from 6 Mbps at 5 am to 0.9 Mbps at 8–9 pm while the coverage measurements stay the same. If this were pure coverage, the morning figure would be equally bad. The evening drop is load, not signal.
So: weak coverage plus peak-hour capacity limits. One fix will not solve both, and a booster only addresses the first.
2. Rank the possible actions and justify the first RF action. What would you do about the peak-hour throughput problem?
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Ranking by cost, speed and reversibility:
- Re-aim azimuth toward the village and reduce downtilt - negligible cost, one week, fully reversible. Do this first: it directly addresses the −108 dBm outdoor reading and costs nothing if it fails. Model the new tilt before climbing, and verify with drive/walk tests at the same points used for the original measurement.
- Re-check the co-channel site and PCI/neighbour planning - if SINR stays at 2 dB after re-aiming while RSRP improves to about −95 dBm, interference is the remaining cause and needs a parameter or frequency change, not more power.
- Small cell or operator-approved repeater for indoor coverage, only if the macro fix leaves indoor RSRP below about −105 dBm.
- New tower - last resort, given 8–10 months and limited budget.
For the evening congestion: RF changes will not add capacity. Options are a capacity carrier or additional sector, temporary data offload to Wi-Fi hotspots at public points, or honest expectation-setting on peak-hour speeds. Measure busy-hour PRB utilisation before promising anything.
3. The panchayat demands a booster in every house. Explain why that is not the right answer, and set out an interim solution you can actually deliver within a month.
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A booster amplifies whatever it receives, including noise and interference. With outdoor RSRP at −108 dBm, the donor signal is already marginal, so an amplifier would raise noise as much as signal, degrade SINR, and create uplink interference for other users on the same cell. Unapproved repeaters also cause interference, are not type-approved, and can be seized; the operator would carry the blame. 300 boosters would make the cell worse, not better, and would not fix the 8–9 pm congestion at all.
Interim plan within a month:
- Re-aim and re-tilt the sector, then publish before/after RSRP and throughput at fixed test points so the improvement is verifiable, not a claim.
- If indoor coverage remains poor, install one or two operator-owned, type-approved small cells or repeaters at public buildings (panchayat office, school) rather than 300 domestic units.
- Offer Wi-Fi hotspots for data offload during peak hours.
- Register the new-tower requirement formally so the 8–10 month timeline is on record, with the measurement data attached.
Communicate the measurement numbers, not assurances: people accept 'from −108 to −96 dBm' far better than 'we are working on it'.