Page 44 - ITU Kaleidoscope 2016

2016 ITU Kaleidoscope Academic Conference

with this idea of expansion of the mobile signal in deep sea.
The response was not encouraging from most of the
operators. Eventually Tata Teleservices Ltd. (TTL) agreed
to carry out the pilot along the coast of Raigad district of
Maharashtra looking at societal benefits.

4. EXPERIMENT AND RESULTS

The entire mobile signal extension testing approach was
divided into four phases:
- Proof of Concept (PoC) and Boat Test Drive
- Selection of cellular technology
- Tower installation and commissioning Figure 4. Boat Test Drive 1 - Geo path
- Parametric test based detailed study of major
operator’s signal

4.1 Proof of Concept (PoC) and Boat Test Drive

TTL had spectrum license for CDMA 850 MHz and GSM
1800 MHz in Raigad. TTL modified the orientation of two
sectors of the antenna on one tower to direct GSM and
CDMA signals towards the sea and a signal measurement
boat test drive was done.

4.1.1 Boat Test drive 1 – Baseline study
The RF engineers, fishermen and the fisheries research Figure 5. Mobile signal testing at sea
scientists carried out 11 hour test drive in the deep sea in a
fisher boat. INCOIS Wind direction and speed map were
used to plan and guide the journey. The Southward journey
was done almost in 15-30 KM range from the nearest shore,
whereas northward journey was done almost in 5-12 KM
range from the nearest shore (fig. 4).

Following equipment was used for the test drive (fig. 5):
- CDMA and GSM Tough Book for automatic voice
and data call testing
- GARMIN GPS
- Mobile Phones (Voice and Data calls)
- Automatic Trackers, supported by Manual
observations (Call setup, Quality, data speed,
completion, etc.
- Log books

GSM and CDMA Transmitter (Tx) and receiver (Rx) band
signal power strength was plotted along the geo-coordinates
(Fig. 6). This helped give an idea of the mobile signal
strength at various locations during the trip.
Also, the initial tests revealed that even if a dedicated tower
is setup, which radiates the signal towards the sea, the line
of sight is a major limitation (25-30 KM) because of the Figure 6. Boat test drive results - call quality
earth curvature

The RF Engineers from the TTL Network planning team
4.1.2 Boat Test Drive 2 – GSM and CDMA comparison adjusted the power level, height and the direction of the
antennas at two different locations (towers) (see Results in

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