Software Radio Implementation of SignalingSplitting in Hyper-Cellular Network

Tao Zhao, Pengkun Yang, Huimin Pan, Ruichen Deng,Sheng Zhou, Zhisheng Niu

Network Integration for Ubiquitous Linkage and Broadband(NiuLab)Tsinghua University, Beijing, China

1 / 18

Outline

1 Introduction to Hyper-Cellular Network

2 Signaling Splitting in Current Protocols

3 Software Defined Radio Implementation

4 Summary

2 / 18

Outline

1 Introduction to Hyper-Cellular Network

2 Signaling Splitting in Current Protocols

3 Software Defined Radio Implementation

4 Summary

3 / 18

Current Cellular Networks

Exponential growth of traffic demand

Smaller cell size & denser base station deployment

Challenges:Energy consumption: BS sleeping → coverage holesInter-cell interference: CoMP → lack of global infoFrequent handovers: signaling overhead

Conventional cellular network

Coupling ofsignaling and datarenders the systeminefficient!

4 / 18

Hyper-Cellular Network Architecture

Control data separation (Signaling splitting)Signaling base station (SBS) & data base station (DBS)Benefits

Green with DBS sleepingSBS holds global information for CoMPHandover only necessary when switching SBS

GREEN: Globally Resource-optimized & Energy-Efficient NW

Hyper-cellular network[1]

[1] Z. Niu et al. “Energy efficiency and resource optimized hyper-cellular mobile communication system architectureand its technical challenges”. In: SCIENTIA SINICA Informationis 42.10 (2012). In Chinese, pp. 1191–1203. doi:10.1360/112012-433.

5 / 18

Service Flow in HCN

MU associates to Signaling BS.

MU requests for traffic channel,Signaling BS assigns a Data BSand informs MU.

Traffic data transmission is estab-lished between MU and Data BS.

6 / 18

Outline

1 Introduction to Hyper-Cellular Network

2 Signaling Splitting in Current Protocols

3 Software Defined Radio Implementation

4 Summary

7 / 18

Challenges & Approach

Why current protocols?Step from design to practice: feasibility of separationMigration of networksFuture protocol design

ChallengesMillions of signals, difficult to categorizeComplicated signal interactions, difficult to separateSeamless UE experience, difficult to guarantee

Solution: separate by network functionalitiesSignaling BS: synchronization, broadcast of systeminformation, paging, low speed data transmissionData BS: synchronization, high speed data transmission

8 / 18

Mapping

State-functionality mapping

Functionality-signal mapping

State-functionality mapping[2]

State UE Activities

Network Functionalities

Syn.

Broadcast of

System

Information

Paging Multicast Unicast

Detached Cell Selection √ √

Idle

Acquisition and Update of System

Configuration√ √

Monitoring of Upcoming

Transmission Notification√

Cell Reselection √ √

Receiving of MBMS √

Active

Acquisition and Update of System

Configuration.√ √

Monitoring of Upcoming

Transmission Notification√

Cell Handover √ √ √

Receiving of MBMS √

Transmission of UE-Specific Data √

[2] X. Xu et al. “On Functionality Separation for Green Mobile Networks: Concept Study over LTE”. . In: IEEECommunications Magazine 51.5 (2013), pp. 82–90. issn: 0163-6804. doi: 10.1109/MCOM.2013.6515050.

9 / 18

Channel Separation

Channel separation scheme for 3GPP standards:

3GPP Standard

GSM/GPRS UMTS R99 LTE R8

SBS

BCCH, PCH,AGCH, RACH,PBCCH, PPCH,PAGCH, PRACH

S-CCPCH,P-CCPCH, MICH

PBCH, PMCH,PRACH

DBS PDTCH DPDCH –

BothSCH, FCCH, TCH,SACCH, SDCCH,FACCH, PDCCH

SCH, CPICH,DPCCH, S-CCPCH

PSS, SSS, PDSCH,PCFICH, PHICH,PDCCH, PUCCH,

PUSCH

Implementation for GSM/GPRS protocol

10 / 18

Outline

1 Introduction to Hyper-Cellular Network

2 Signaling Splitting in Current Protocols

3 Software Defined Radio Implementation

4 Summary

11 / 18

Platform

Hardware:Commodity PCUSRP N210Gigabit Ethernet SwitchMobile phone

Software:OpenBTSosmocomAsterisk

Switch

Data BS Signaling BS Data BS

Data Traffic

Control Signaling

MU1 MU2

SBS RF DBS RFDBS RF

OpenBTS PCU SGSN GGSNInternet

SDR platform

12 / 18

Main Work

SBS DBS communicationUDP socketsPayload: channel description

SynchronizationFrequency: MIMO cable; GPSDOTime slot: wakeup; correlation

Simplified DBS

13 / 18

Progress

Phone call separation

GPRS data separation

Platform setup

SBS log

DBS log

14 / 18

Vision

Hyper-cellular network testbedTypical work flowBS schedulingPerformance evaluation. . .

15 / 18

Outline

1 Introduction to Hyper-Cellular Network

2 Signaling Splitting in Current Protocols

3 Software Defined Radio Implementation

4 Summary

16 / 18

Summary

Hyper-cellular network enables GREEN networkoperations for cellular networks.

Functionality separation approach to achieve signalingsplitting

Working system on software defined radio platform

17 / 18

18 / 18