5G能源效率:关键概念和潜在技术

减少网络能耗的高能源效率目标是5G的关键要求。它能够降低总投资成本,促进网络连接延伸到偏远地区,并以可持续发展和资源合理利用的方式提供网络的接入。本文为建立高能源效率的5G系统制定了两个设计原则,同时提出了实现这些的关键技术——包括超简设计、先进的波束赋型技术、在无线接口上用户数据和系统控制层面的分离,以及网络功能虚拟化和云计算技术。

Secure Packet Video Transmission over Wireless Multimedia Sensor Networks

This paper proposes a packet scheduling scheme thatoptimizing the coded video transmission overmultipath wireless multimedia sensor networks interms of received video distortion and power efficiencyenhances the security aspects of the underlyingsystem.When the aggregate transmission rateavailable at the network cannot support the requiredtransmission rate,the scheduling algorithm can selectivelydrop combinations of video packets prior totransmission to adapt the rate of the sender to thelimitations of the wireless channel capacity.Twoscheduling algorithms are proposed.The Baselinescheme utilizes a novel distortion prediction modeland decides upon which packet can be dropped priorto transmission based on the packet’s impact on thevideo distortion.In addition to the bandwidthlimitations,the Power aware packet scheduling is an extension of the Baseline capable of estimating thepower that will be consumed by each node during thetransmission;hence it can control the power consumptionby selectively drop packets of low importanceto the decoded video.Simulation results indicatethe efficiency of the proposed scheduling schemein terms of received video distortion(PSNR)andpower consumption.

Distributed Relay Diversity Systems for OFDM-Based Networks

In this paper, distributed relay diversity systems are analyzed, modeled and evaluated in an Orthogonal Frequency Division Multiplexing (OFDM) based networks. The investigated distributed relay diversity schemes extend the ideas of a single hop transmit antenna schemes such as Cyclic Delay Diversity (CDD), Space Time Transmit Diversity (STTD), transmit Coherent Combining (CC) and Selection Diversity (SD) to distributed diversity systems. In contrast to the classical single hop system, the antennas in the distributed systems belongs to distributed relays instead of being co-located at the transmitter. The distributed relay diversity methods considered in this paper: Relay CDD (RCDD), Relay Alamouti (i.e.STTD), Relay CC (RCC) and Relay SD (RSD) are compared to the traditional 1-hop system. Analytical expressions for the received Signal to Interference Noise Ratio (SINR) are derived and used in a dynamic multi-cell multi-user simulator. Results show considerable SINR gains for both Round Robin and Max-SINR schedulers. The SINR gains translate into substantial cell throughput gains, up to 200%, compared to 1-hop systems. Despite its low complexity, the RCDD scheme has similar performance to that of other more sophisticated 2-hop schemes such as Relay Alamouti and Relay Coherent Combining. Marginally better results are observed for the Relay Selection Diversity scheme.

Gripper Design for Radio Base Station Autonomous Maintenance System

For an autonomous system to perform maintenance tasks in a networking device or a radio base station(RBS), it has to deal with a series of technological challenges ranging from identifying hardware-related problems to manipulating connectors. This paper describes the development of a robot maintenance system dedicated to detect and resolve faulty links caused by unplugged or poorly connected cables. Although the maintenance system relies on four subsystems, we significantly focus on our low-cost and efficient custom gripper solution developed to handle RJ45 Ethernet connectors. To examine our gripper, we conducted three experiments. First, a qualitative questionnaire was submitted to 30 users in the case of the teleoperated scenario of the gripper attached to a robotic arm. Similarly, we also tested the automatic operation mode. The results showed that our system is reliable and delivers a highly efficient maintenance tool in both teleoperated and autonomous operation modes. The practical experiment containing the removal or unplugging of connectors demonstrated our gripper′s ability to adequately handle these, whereas the feedback from the questionnaire pointed to a positive user experience. The automatic test assessed the gripper′s robustness against the continuous operation.

Capacitive actuation and switching of add–drop graphene-silicon micro-ring filters

We propose and experimentally demonstrate capacitive actuation of a graphene–silicon micro-ring add/drop filter. The mechanism is based on a silicon–SiO_2–graphene capacitor on top of the ring waveguide. We show the capacitive actuation of the add/drop functionality by a voltage-driven change of the graphene optical absorption. The proposed capacitive solution overcomes the need for continuous heating to keep tuned the filter's in/out resonance and therefore eliminates "in operation" energy consumption.

Model-based reinforcement learning for router port queue configurations

Fifth-generation(5G)systems have brought about new challenges toward ensuring Quality of Service(QoS)in differentiated services.This includes low latency applications,scalable machine-to-machine communication,and enhanced mobile broadband connectivity.In order to satisfy these requirements,the concept of network slicing has been introduced to generate slices of the network with specific characteristics.In order to meet the requirements of network slices,routers and switches must be effectively configured to provide priority queue provisioning,resource contention management and adaptation.Configuring routers from vendors,such as Ericsson,Cisco,and Juniper,have traditionally been an expert-driven process with static rules for individual flows,which are prone to sub optimal configurations with varying traffic conditions.In this paper,we model the internal ingress and egress queues within routers via a queuing model.The effects of changing queue configuration with respect to priority,weights,flow limits,and packet drops are studied in detail.This is used to train a model-based Reinforcement Learning(RL)algorithm to generate optimal policies for flow prioritization,fairness,and congestion control.The efficacy of the RL policy output is demonstrated over scenarios involving ingress queue traffic policing,egress queue traffic shaping,and one-hop router coordinated traffic conditioning.This is evaluated over a real application use case,wherein a statically configured router proved sub optimal toward desired QoS requirements.Such automated configuration of routers and switches will be critical for multiple 5G deployments with varying flow requirements and traffic patterns.