Device to Device Communication in LTE Networks.

1. New Handoff Management for D2D Communication in
Long Term Evolution-Advanced Cellular Network
Mohammad Dabibi
University of Tehran
m.dabibi@ut.ac.ir
December 12, 2014
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 1 / 34

2. Headline
1 Introduction to Device To Device Communication
Proximity Discovery and Awarness
Classification of D2D Communication
Current Progress in Standardization
2 LTE-A Access, Core and Procotol Architecture for D2D
D2D Function Block in LTE-A SAE Architecture
Protocol Stock and Bearer Management
Communication Senarios
D2D Connection Request/Setup
3 Handover Thechnology
Target Cell Selection
X2 Backhauling and Handover Using X2
Proposed LTE handover using D2D
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 2 / 34

3. What is D2D?
Direct Communication Between Nearby Mobiles.
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 3 / 34

4. How To Get Proximity Awareness?
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 4 / 34

5. Discovery And Broadcast
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 5 / 34

6. User Experience
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 6 / 34

7. User Experience Cont’n
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 7 / 34

8. User Experience Cont’n
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 8 / 34

9. User Experience Cont’n
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 9 / 34

10. User Experience Cont’n
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 10 / 34

11. User Experience Cont’n
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 11 / 34

12. Classifiation of D2D Communication
• Licensed Band: Better interference avoidance under a controlled
environment. Ex. Femtocells / Picocells Under LTE-A
licensed band
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 12 / 34

13. Current Progress in D2D Communication
• June 2011: Study item description on the radio aspect of D2D
descovery and Communication by Qualcomm
• Augest 2011: Direct over-the-air LTE D2D discovery and
Communication
• June 2012: Identified potential requirements between proximate devices
as new step on Rel-12
• December 2012: Study on LTE Proximity Service in radio Access
Network ( D2D Discovery - D2D Communication )
• Current Work On: Discovery Signal design, Resource Allocation and
Scheduling, Synchronization mechanism.
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 13 / 34

14. D2D Function Block in LTE-A SAE Architecture
• ProSe: Proximity Discovery - Direct Communication
• D2D Sessions: D2D session Could be initiated by sending an initiation
request to the Proximity Server in MME.
• Radio Bearer Setup (Ud): MME is responsible for initiating Ud
interface.
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 14 / 34

15. D2D Function Block in LTE-A SAE Architecture Cont’n
• Radio Bearer Setup (Ud): MME is responsible for initiating Ud
interface + Delivery IP address for D2D terminal devices.
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 15 / 34

16. Protocol Stock and Bearer Management
• Data Protocol Stock for D2D: D2D bearer has been set up between
peer devices.
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 16 / 34

17. D2D Design Aspect
• Modulation Format: LTE use SC-FDMA for UL and OFDMA in DL. If
SC-FDMA is used, the D2D UE needs to be equipped with a
new SC-FDMA receiver.
• Frame Structure: Camping D2D on UL resources
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 17 / 34

18. D2D Design Aspect Cont’n
• Channel Measurements: Based on measurement reports
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 18 / 34

19. LTE-A Access, Core and Protocol Architecture for D2D
• D2D Communication Scenarios Direct Communication
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 19 / 34

20. D2D Ennhanced LTE Architecture
• New Interfaces PC1, PC2, PC3, PC4, PC5, PC6 and SGi
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 20 / 34

21. Security Architecture for D2D
• Main Security Feature:
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 21 / 34

22. D2D Connection Request
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 22 / 34

23. Handover Technologies
• Hard Handover break-before-make
• Soft Handover make-before-break
• handover procedure: measurements control, the measurements report,
handover decision, handover execution
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 23 / 34

24. Handover Process ( handover Decision )
Handover process may be
triggered by:
1 Quality, filed strength of
Distance Values fall
bellow/exceed their
threshold
2 Periodic Check : Power
Budget HO, Umbrella HO
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 24 / 34

25. Handover Priority
• Handover Priority
1 Uplink and downlink Interference
2 Uplink Quality
3 Downlink Quality
4 Uplink Level
5 Downlink Level
6 Distance
7 Rapid Field Drop
8 Slow moving UE
9 Better Cell, i.e Periodic Check ( power Budget HO or Umbrella HO
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 25 / 34

26. Target Cell Selection
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 26 / 34

27. Handover in LTE-A
• Hard Handover High handover outage probability, Large Delay.
• Aspect on D2D To Provide Steamless access to Voice and Multimedia
service with Strict delay in D2D
• Solution 1. Semi-Soft-Handover 2. Handover Using D2D
Communication
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 27 / 34

28. Backhauling X2
• X2 The LTE Radio Access Network moves RNC functionality ro
the eNodeB and introduced a new X2
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 28 / 34

29. LTE X2 Handover High Level Flow
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 29 / 34

30. LTE X2 Handover High Level Flow Cont’n
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 30 / 34

31. Proposed LTE D2D Handover
• Proposed: Handover During D2D Communication via Ud
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 31 / 34

32. Proposed LTE D2D Handover High Level Flow
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 32 / 34

33. References
T. S. Rappaport
Wireless communications, Prentice Hall, 1996
C. Lin, K. Sandrasegaran and S. Reeves
Handover Algorithm with Joint Processing in LTE-Advanced 2012 IEEE
J. Chang, Y. Li, Sh. Feng, H. Wang, C. Sun, Ph. Zhang
A Fractional Soft Handover Scheme for 3GPP LTE-Advanced System, IEEE
International Conference, 2009.
M. Anas, F. D.Calabrese, P. E. Mogensen, C. Rosa, K. I. Pedersen
Performance Evaluation of Received Signal Strength Based Hard Handover for
UTRAN LTE, IEEE Vehicular Technology Conference, 2007, pp.1046-1050.
K. Doppler, M. Rinne, C. Wijting, C. Ribeiro, and K. Hugl
Deviceto-device communication as an underlay to lte-advanced networks,
Communications Magazine, IEEE, vol. 47, no. 12, pp. 4249, 2009.
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 33 / 34

34. The End
Mohammad Dabibi (University Of Tehran) D2D Handover December 12, 2014 34 / 34