Sean Cai

Li Mo

T his special issue of ZTE Communications focuses on recent advances in mobile data communications for the ICTand telecommunications industries.The ever-increasing amount of mobile data traffic has been the subject of many studies.This research area is widely applicable to contemporary technology and network optimization techniques.

The priority of most operators is to further expand their existing 3G networks and focus on new 3G technologies being developed to meet ever-increasing data traffic and data speed.Optimization techniques of 3G and 4G networks are being explored in order to improve network performance.Today,operators are concerned about adopting the right backhaultechnologies,leveraging existing Wi-Finetworks to offload data traffic,building and evolving the core network,and introducing mobile cloud computing in order to support expanded business in the future.

In this special issue of ZTE Communications,we called for papers that provide greater insight into improved mobile data networks.Inter cell interference coordination(ICIC),coordinated multipoint transmission(CoMP),multiple input multiple output(MIMO),adaptive beamforming,and network load balancing(NLB)are introduced.These techniques may require operators to review the way they engineer and deploy their networks.Techniques to further improve network performance are discussed in this issue.High-level backhaul technologies and core network evolution paths are also discussed in this issue.

In“Enhanced Cell Edge Performance with Transmit Power Shaping and Multipoint/Multiflow Techniques,”by Philip Pietraskiet al.,a new concept called Fuzzy Cells is introduced to improve cell coverage.Fuzzy Cells enable user equipment(UE)to access the full system bandwidth in a sector by using a component carrier(CC)transmitted at higher power than the other CCfrequencies.If at least three CCfrequencies are used,three sets of cell boundary locations can be created so that no UEis simultaneously in the cell-edge region for every CC.Cell coverage can be improved using the techniques proposed in the article.

In“Spatial Load Balancing in Wide-Area Wireless Networks,”by Kambiz Azarian et al.,NLB and single-carrier multilink(SCML)are compared.These techniques are used to increase network capacity and improve user experience.In NLB,each sector-carrier periodically provides its loading information in order to improve overall network performance.In SCML,the combined burst rate of a UEcan be significantly improved between neighboring cells.

In“Uplink Power Control for MIMO-OFDMA Cellular Systems,”by Rongzhen Yang,uplink power control algorithms,including FPC used in 3GPPLTEand LTE-Advanced,are compared.A novel power control algorithm is proposed for MIMO-OFDMAsystems.A simplified maximum sector throughput(SMST)algorithm is also proposed to maximize the sector throughput by adjusting uplink transmit power.

In“Mobile Backhaul Solutions,”by Li Mo et al.,mobile backhaul requirements are reviewed,and backhaul solutions are proposed with timing synchronization,multiprotocol label switching(MPLS);operation administration,and maintenance(OAM),and protection taken into consideration.

We thank allthe authors for their excellent papers and the reviewers that had helped us with their careful and detailed critical reviews.We are very grateful to the editorial board for their helpful suggestions in improving the quality of the papers in this issue.