Now a day smart phone users are increased and the energy consumption problem in mobile industry has become crucial. For the growth of mobile industry energy efficiency of the system must be improved. In order to improve the methods of network energy usage usually reduction of the Base Stations are to be employed. The mobile industry faces a critical energy consumption challenge. By 2014 smart phones will exceed 1.82 billion units and surpass PCs as the most common web access devices. That’s why it is one of the important things. As all know that a smart is mainly for easy access to the network at anytime and anywhere. So it employs powering up all the Radio Base Stations (RBS’s) at maximum power. Since there are more number of service providers competition exist at the field of telecommunication. So it yields in more energy consumption to get monopoly among them. In the field of engineering, a system is usually designed to transform energy to useful work. Energy Efficiency can therefore be defined as the ratio of useful work to the total supplied energy. The useful work in a communication system refers to the effort to deliver modulated signals for information exchange. The definition of Energy Efficiency varies according to measured objects. There are two basic methods to measure Energy Efficiency. One way is to define Energy Efficiency as the ratio of efficient output power/energy to total input power/energy. This definition is widely used by systems and components such as power supply, Power Amplifiers, and antennas. The other way defines Energy Efficiency as the performance per unit of energy consumption. The seminar gives a brief description about the methods to manage the network energy even when the on time access to network by mobile phones. Also gives a summary about existing and latest methodologies about the management in RBS’s.

1. 8/7/2014
1SNMIMT Dept. OF EEE

2. MADHAVADAS M
S7 EEE
ROLL NO. : 24
8/7/2014 2SNMIMT Dept. OF EEE
Guided by,
ANOOJA C L
Asst. PROFESSOR
Dept. OF EEE

3. 1. INTRODUCTION
2. ENERGY EFFICIENCY
3. RBS ENERGY CONSUMPTION
4. ENERGY SAVING METHODS
 TIME DOMAIN
 FREQUENCY DOMAIN
 SPATIAL DOMAIN
5. COMPARISON
6. CONCLUSION
8/7/2014 3SNMIMT Dept. OF EEE

4. Mobile industry is facing a crucial energy crisis.
Increase in network data volume caused high energy demand and
increased CO2 emission.
Energy is consumed by the network components not only to deliver
signals, but also for cooling, cabling, converting etc.
All methods in this topics are for Long Term Evaluation (LTE)
scheme.
Soft methods such as signal modification cause only a small
reduction of energy usage.
8/7/2014 4SNMIMT Dept. OF EEE

5. ♥ Effort to deliver modulated signals for information exchange
(WIRELESS EE).
♥ Increase in network data volume caused increase in energy
consumption by Radio Base Stations(RBS).
♥ All cellular companies are only focused on performance.
♥ Global System for Mobile communication have EE of RBS
side about 3.1% in case of 3G it’s about 20%.
8/7/2014 5SNMIMT Dept. OF EEE

6. ENERGY EFFICIENCY
Ratio of efficient
output power/energy
to total input
power/energy
Performance per unit
of energy
consumption
8/7/2014 6SNMIMT Dept. OF EEE

7. R- Bit rate of information B- Band width
P- Received power N0- Noise power spectral density
Unit – Bits/Joule
8/7/2014 7SNMIMT Dept. OF EEE

8. 8/7/2014 8SNMIMT Dept. OF EEE

9. The most power consuming equipment in RBS is Power Amplifiers
(ie. PA’s).
Shutting down PA offers less energy consumption.
Contd…
8/7/2014 9SNMIMT Dept. OF EEE

10. 8/7/2014 10SNMIMT Dept. OF EEE

11. 4.1.1 PA off at signal free
› Straight forward approach.
› PA operation time ≈ 47%.
8/7/2014 11SNMIMT Dept. OF EEE

12. 4.1.2 Multicast Broad cast Single Frequency Network
(MBSFN)
› Reference signal reduction.
› Used to provide services like mobile TV.
› PA operation time ≈ 28%.
8/7/2014 12SNMIMT Dept. OF EEE

13. 4.1.3 Extended cell Duplex Transmission (DTX)
› Further reduction of RS’s.
› If no downlink, no need to transmit 1-4&6-9 sub frames.
› PA operation time reduced to 7.1%.
 Reduction of PA on time; used at rural areas.
 Unpredictable problems while synchronizing with user.
 In DTX mode a pilot design is required.
 Used in a single RBS. 8/7/2014 13SNMIMT Dept. OF EEE

14. 4.2.1 Band Width Reduction
› Band width is reduced when increase in downlink takes
place.
› Frequency change must be within the standard limits.
› Either change in carrier frequency and bandwidth or
change in bandwidth without changing carrier frequency is
employed.
› PA’s are not shut down; But it drain less energy than usual.
8/7/2014 14SNMIMT Dept. OF EEE

15. 4.2.2 Carrier aggregation
› In an RBS carriers are aggregated in groups & each group
is served by individual PA’s.
› When an aggregate downlink is absent, corresponding PA
can be shut down.
 Efficiency of frequency domain is limited.
 Normally combined with energy saving methods of other
domains.
 Less impact on User Evaluation.
 Used in a single RBS. 8/7/2014 15SNMIMT Dept. OF EEE

16. 4.3.1 Reduce antenna number
› Most commonly used method.
› Combined with bandwidth reduction technique for low
traffic mode.
› To maintain same strength of spectrum, additional control
signals are needed.
› May lead to service degradation and interruption.
8/7/2014 16SNMIMT Dept. OF EEE

17. 4.3.2 Switch on/off cell
› When traffic load is low, some cells can be shut down.
› A set of cells where shut down and User Evaluation is handle
over to remaining cells.
› The cells are either shut down by direct signaling between
RBS’s, or by providing sequential control.
› Another approach is Hierarchal Cell Structure (HCS), Here
macro cells are always on for coverage and micro cells are used
to boost capacity. And are operates at heavy loads.
8/7/2014 17SNMIMT Dept. OF EEE

18. 4.3.3 Layered structure
› Same as HCS, macro cells serve wireless wide area network and micro
cells serve local area network.
› Macro cells can be shut down by transferring loads to micro cells.
› Improved energy efficiency and coverage are obtained.
› Flexible than HCS.
Can be extended up to network basis and is more flexible.
8/7/2014 18SNMIMT Dept. OF EEE

19. › Combination of different domain solutions are used to attain
maximum EE.
In low down link traffic single carrier under carrier
aggregation method with single antenna and maximum
MBSFN sub frames in a frame.
› Reducing antenna number and bandwidth cause reconfiguration
time about 10ms.
› Hybrid solutions are recommended only in semi-static traffic
conditions. 8/7/2014 19SNMIMT Dept. OF EEE

20. 8/7/2014 20SNMIMT Dept. OF EEE

21. Merits
› Low power
consumption.
› Improved downlink
speed.
› Increased data volume
capacity.
Demerits
› Bulkier circuit.
› High installation cost.
› Need of regular
maintenance.
• In full load cases hybrid solutions are employed
• At no load cases DTX or MBSFN is employed.
• MBSFN at no load gives high performance.
Contd…
8/7/2014 21SNMIMT Dept. OF EEE

22. Energy consumption problems in wireless networks
can be reduced by energy saving LTE systems.
Energy Efficiency of RBS varies with traffic
problems. And it can be reduced by Tri- Dominal
approch.
Most of the approaches, hybrid approach gives best
result.
8/7/2014 22SNMIMT Dept. OF EEE

23. IEEE Wireless communication.
Wikipedia the free encyclopedia.
Bharath Sanchar Nigam Limited.
Finnish Funding Agency for Technology and Innovation.
B. Gammage et al., “Gartner’s Top Predictions for IT Organizations and
Users, 2010 and Beyond: A New Balance,” Gartner Report, Dec. 2009.
R. Tafazolli et al., “eMobility Mobile and Wireless Communications
Technology Platform: Strategic Applications Research Agenda,” Net!Works
European Technology Platform, July 2010, http://www.networksetp.eu8/7/2014 23SNMIMT Dept. OF EEE

24. 8/7/2014 24SNMIMT Dept. OF EEE