1 | P a g e

Smart Metering | Why Power Line Communication Is

Best Suited For India.

Smart Metering for India

Smart Metering represents an enormous opportunity to transform how India uses,

consumes and thinks about energy. Smart Metering educates both the utility and the

consumer on how the energy is put to use.

India has at least 27% Transmission and Distribution losses (T&D) across various utilities

in India, which is among the highest in the world. One of the primary reasons for such

huge losses is lack of proper measurement mechanisms at various stages till the power

reaches the end point. With Smart Metering in place it is possible to indicate Losses apart

from Energy Audit, Demand Response, Peak Demand Shaving, TOD, Prepaid etc.

Communications in Smart Metering is the core of the entire Smart Metering solution

to make the above wish list a reality. A reliable communication is the need of the

hour in the Indian Smart Metering space.

2 | P a g e

3 out 5 Smart Meters shipped globally is on PLCC

3 | P a g e

Comparison between RF, GPRS and Power Line

Communications Coverage

� Towers

PLCC by its intrinsic nature can reach up to the last Meter which is connected to electrical

line. RF communications would also be able to reach to the last Meter without an

additional external entity. Whereas GPRS signals has dependency on the Service Provider.

� Access Points

Meters get installed at different locations in Individual homes, High rise buildings, Cellars

etc. High rise buildings are made up of high amount of steel and concrete. Meters could

also be installed inside a Metal enclosure and/or in the basement of the building. RF and

GPRS will face serious challenges in such a scenario. Such a scenario has no implication

on Power Line Communications. High rise buildings could be ideal for Power Line

Communications considering the compactness of the Meter installations, better quality of

wiring. The Physical location of the Meter installations has an implication on the RF &

GPRS communications and very little or no implication on Power Line Communications.

� Topography

If the region of deployment is hilly the impact could be probably more in the case of RF,

whereas PLCC performance would not get affected. GPRS could also be uncertain and

unpredictable.

Performance

� Range

PLCC signals easily propagate up to a KM if the line conditions are less noisy (>-80dB).

But in a real / harsh field conditions the signals will propagate at least up to 80 meters in

very noisy conditions (-50dB).

RF signals have propagation capabilities of up to 100 meters line of sight and in all

practical cases the signals can only reach up to 30 meters. GPRS signal propagation is

entirely under the control of the Service Provider.

4 | P a g e

� Data rate / Bandwidth

Narrow band PLCC signals will generally communicate between 2Kbps to 10Kbps. RF

signals can communicate up to 100Kbps. Data rate and Bandwidth availability in GPRS is

significantly greater than both PLCC and RF reaching up to 1Mbps

� Latency

In Narrow band PLCC & RF, the point to point communication latency is between 700ms

to 1500ms depending on the number of hops (repeaters) between the Meter and the

DCU. GPRS communication would also need around 1000ms for propagation since the

communication would involve the Service Providers medium.

� Customer Type

PLCC or RF solutions will be appropriate in deployments catering to

In the case of LT residential consumers each transformer would be probably be catering

to25-500 households and the installation Meter with PLCC/RF communication will be

justifiable.

Any industrial (HT Consumers) electrical topology would favor using GPRS or RF based

Meters over PLCC. Considering the density (sparsely spaced) of the Meters installed RF

would be ruled out and GPRS would be an ideal media to use.

� Time of the Day

Utility would generally be interested in EOD data from the Smart Meters, upon which all

the analytics would be built upon. Once in a day (24 hours) data pull/push is all that the

Data Centre would need from all the Smart Meters.

Residents tend to not to use most of the electrical equipment’s during the night (in LT

network), this makes the power line cleaner during the nights. Signal quality and

performance in PLCC network peaks during the midnight hours (12AM to 6AM) and most

of the communication can successfully take place during those hours.

GPRS signal quality also can be expected to be slightly improved during the night

compared to the day.

This kind of distinct advantage is not available for RF.

5 | P a g e

Communications Network Power Line is a property of the Utility, so no additional communication infrastructure is

needed until a certain point in the network (till DCU).

RF will use the wireless media to communicate but it uses a free band.

GPRS will have dependency on the cellular network and unless M2M platforms are not

utilized, the Service Provider will always try to prioritize voice calls over the GPRS

connectivity.

In the process of improving the quality of service in either of the communications, it makes

a lot of sense for the utility to choose PLCC as the communication medium, since

eventually the Utility will also improve upon the (T&D losses) quality of power distributed

along with the improvement on communication medium.

Asset Mapping, Management & Energy Audit Real-time Asset Mapping and Management only possible using PLCC Network – How

does it work?

• Power Line signals do not cross over between Distribution Transformers, this factor

plays an important role in Real-time Asset Management.

• As a onetime activity during installation, DCUs are mapped with DTs.

• All Meters or Communications devices under the DCU are thereby mapped to the DTs

effortlessly.

• Automatic Consumer Indexing (Meters, DTs etc).

• Generates Tree Structure / Mapping dynamically as and when Meters Register with

the DCU

• Energy Audit for thousands of DTs is effortless since DCU wise Meter data is available

at central repository and DCUs are mapped DT wise. This feature is uniquely fool proof

and uncomplicated unlike in RF and GPRS.

Data networking at affordable costs

� Modem Costs

RF modems are around Rs300, PLCC modems around Rs700, whereas GPRS modems are the most

expensive at around Rs1000 (for 2G modules)

� Equipment Costs

6 | P a g e

Each solution has its own uniqueness and limitations. In RF solutions, a single DCU can handle

around 40 nodes (Smart Meters). In case of PLCC solutions, a single DCU can handle minimum

100 nodes and up to 200 nodes, depending on the power line infrastructure. Since GPRS Meters

directly link with the server there is no necessity for any DCUs.

Effectively, in RF solutions, DCU quantities is 2.5 times than that of a PLCC solution.

In Smart Meter communications, a “Signal Repeater” equipment plays an important role to boost

signal quality in the network. In either, RF or PLCC solutions the Smart Meters can act as repeaters.

But specifically in RF solutions there would be a need to install devices exclusively for signal

boosting to overcome “line of sight” issues which is never an issue in PLCC.

For an every network of a DCU and 40 nodes, we can consider to have atleast 2 “Signal

Boosters/Repeaters” to overcome bends and obstructions in the installation area.

GPRS systems may need external antenna and signal boosters in places where the GPRS signal

quality is very poor. Most of the Meter installations in India can be found in the basements or

under the stairs.

RF solutions are ideal for countries such as USA, where wooden houses are common and line of

sight issues are lesser.

� Installation Costs

Power line signals from the Smart Meters cannot hop over the Distribution Transformer (DT). This

makes the installation process simple since the survey and planning of each of the networks under

a DT is independent (since no signal interference between two communications networks of

different DTs) and modular. Therefore the placement of the DCU does not require expert planning

and can be taken up by unskilled staff.

This kind of luxury is not available for the RF systems since there is signal interference between

each of the networks. Survey and planning should be undertaken extensively to mitigate under

performance and signal interference issues. Placement of DCU is very critical and requires field

tools training to execute.

Though, GPRS systems does not require any kind of would not need any skilled resources for the

installations.

� Operation & Maintenance

PLCC systems are self-healing and would require very less maintenance. Therefore very less

recurring expenses associated with it.

Though, RF systems are also self-healing in nature, because of the signal interference of nearby

networks is high and absence of “isolated independent” networks are absent (unlike in PLCC), it

would require regular maintenance from trained and skilled resource.

In GPRS based systems, there will be a per node monthly recurring expense towards the usage of

the telecom network.

7 | P a g e

Summary of Comparison

Sameer Patil | Head-Smart Metering

PowerOneData, Bangalore