Cellular coverage plays a pivot role in throughput enhancement.
The major challenge faced by the network operators today is to provide uniform coverage especially
in metro cities which are filled with high rise buildings.
One way to expand the existing Macro network is to densify it by adding more eNodebs.
However installing macro sites can be very expensive.
So how do we overcome this challenge?
Hello Everyone, welcome back to the fundamentals of LTE.
Today we will be discussing how coverage is improved using Heterogeneous network and Relay nodes.
Now, There are several techniques to i mprove the Coverage -
The simplest method is by Introduction of
small cells, through the addition of low-power base stations or eNodeBs.
They are primarily added to increase the capacity in hot spots with high user demand and to
fill in areas which are not covered by the macro network.
They can be used both outdoors and indoors.
They also improve network performance and service quality, by offloading from the large
macro-cells.
The result, is a heterogeneous network with large macro-cells, in combination with small
cells, providing increased bitrates per unit area.The heterogenous network, may consist
of macro, micro, pico and femto cells, based on the eNodeB power.
Another way of improving coverage is by using Relay Nodes.
The LTE relay is a fixed relay-infrastructure without a wired backhaul connection, that
relays messages between the base station and mobile stations through multihop communication.
The Relay Node is connected to a Donor eNodeB.
From UE perspective the Relay Node will act as an eNodeB and from the Donor eNodeb perspective
the Relay Node will be seen as a User Equipment.
It is different from the use of repeater.
A repeater simply rebroadcasts the signal.
So the Signal to noise ratio reduces.
But A relay will actually receive the signal, demodulate and decode it, apply any error
correction to it and then retransmit a new signal.
In this way the signal quality is enhanced.
LTE Relay nodes has several advantages - 1. Increase network density:
LTE relays are small and do not require separate Backhaul.
Enabling them to be installed in many convenient areas.
E.g on street lamps, on walls etc. so they can be used to ensure good signal level are
received by all users.
2. Network coverage extension : With no need to install a complete base station, the relay
can be quickly installed.
so that, it fills in the coverage blackspot.
With high gain antennas placed in suitable locations it is possible to provide good communications
between donor eNodeB and the node situated outside the coverage area.
Thus, LTE relay nodes can be used to increase the coverage outside main area.
Additionally the relay nodes may be cascaded to provide considerable extensions of the
coverage.
3. Rapid network roll-out: Without the need to install backhaul, or possibly install large
masts, LTE relays can provide a very easy method of extending coverage during the early
roll-out of a network.
More traditional eNodeBs may be installed later as the traffic volumes increase.
The third method of improving coverage is by using Remote Radio Heads to existing macro-eNBs.
RRHs connected to an eNodeB via fibre can be used to provide small cell coverage.
So Friends, We have seen some of the techniques used to improve the coverage.
In our next video we will discuss how performance at cell edge or at converging cells can be
improved using Coordinated Multipoint.
You can post your doubts in the comment section.
Happy Learning.