Green Cellular Networks: A Survey, Some Research

Issues and Challenges

Nourah AlhassounFebruary 29, 2012

Part IObjective:

A brief survey of methods to improve the power efficiency of cellular networks and explore some research issues and challenges

Suggest some techniques to enable an energy efficient or green cellular network

Results:

A survey on methods to obtain energy savings in base stations such as architectural changes in base stations and heterogeneous network deployment

Propose a research vision by using some techniques(cognitive radio and cooperative relaying technologies) to make energy more efficient

Part II

Important Aspects of a Green Networking:

I. Defining Green Metrics

II. Architecture Changes in Base Stations

III. Network Planning

IV. Addressing Energy Efficiency in Future Generation Wireless Systems

V. Some Broader Perspectives

I. Measuring GreennessEnergy Efficiency Metrics:

Facility-level: High-level systems where equipment is deployed

Equipment-level: Evaluate performance of an individual equipment

Network-level: Assess the performance of equipment with the consideration of features and properties

II. Architecture: Energy Saving in Base Stations

Minimizing BS Energy Consumption Improvements in Power Amplifier: Switch mode

PAPower Saving Protocols: Sleep Mode

Energy Aware Cooperative BS Power ManagementCell Zooming: BS can adjust its size according to

network or traffic situation

Renewable Energy ResourcesSolar and Wind Energy instead of off-grid sites

III. Network PlanningHeterogeneous Network Deployment:

Based on smaller cells such as micro, pico and femtocells

Advantages: Energy consumption of the network can be reduced up to

60% compared to a network with macro-cells only Smaller cells use higher frequency bands to provide high

data rates

Draw Backs: The efficiency of macro-cell Base Station might be

reduced

Enabling Technologies:

Green Communication via Cognitive Radio:Purpose: Collect information on the spectrum

usage and access the unused frequency bandsManage the spectrum optimally and dynamically

Green Communication delivered by Cooperative Relays:Purpose: Improvement in throughput and coverageProvide service to more users using less power

Part IIIIV. Addressing Energy Efficiency in Future Generation Wireless Systems

IV. Addressing Energy Efficiency in Future Generation Wireless SystemsLow Energy Spectrum Sensing

Cognitive Radio: design low complex cyclostationary detectors instead of energy detectors

Energy Efficient Resource Management with Applications in Heterogeneous Networks Relay placement, optimal relay selection criterion

Addressing Uncertainty IssuesCognitive Radio: did not take into account the effect

of imperfect sensingCooperative Relays: optimal relays with perfect CSI

VI. Some Broader PerspectiveIdeas to achieve energy efficient cellular network:

Statistical Power Profiles: Dynamic algorithms can be designed to switch BS to different power profile appropriate for that time of the day

Smart Grid Technology:Adding measurement sensors which can update the status of BSs then transmit them to other BSs and smart grid control system

Embodied Energy:Reducing the number of BS since embodied energy accounts for a significant proportion of energy consumed by the BS

Energy Saving Obtained by Some of the Discussed Techniques

Reference

Hasan, Z. Boostanimehr, H. 2011. “Green Cellular Networks: A survey, some research issues and challenges”. IEEE Communications Survey & Tutorials. V13,2,4.