Heterogeneous Mobile Network

Transcription

1 Heterogeneous Mobile Network Dr. Jin Yang Verizon Communications Inc. IEEE ComSoc SCV April 2012

2 Outline Heterogeneous mobile wireless network (HetNet) Deployment scenarios for low-power nodes LTE performance Increase network capacity Improve network mobility UE s role in HetNet HetNet: Benefits and Challenges 2

3 Mobile Traffic Trend Mobile traffic is growing exponentially Various video applications Smartphone, tablet and laptop File sharing and gaming Social networking Machine-to-machine Copyright 2011 Verizon, all rights reserved. Contents provided AS IS and subject to change without notice. 3

4 Heterogeneous Mobile Wireless Network SGW MME HSS PCRF OA&M Radio Access Network Microcell PDN GW Baseband Bank SecGW HeNB GW epdg WiFi Microcell HeNB Enterprise Femto 4

5 Deployment Scenarios for Low-Power Nodes 5

6 CDF [%] LTE Network Performance Baseline Commercial LTE network has achieved a very high performance standard High average user throughputs High SINR and percentage of MIMO rank 2 LTE-Adv is going to further improve the network and user performance Carrier aggregation Interference mitigation Coordinated multipoint Tx/Rx and distributed MIMO UL_SINR_Loaded UL_SINR_UnLoaded DL_SINR_Loaded DL_SINR_UnLoaded SINR Distribution SINR [db] Note: SINR from a trial network 6

7 Increase Network Capacity Interference Mitigation Interference mitigation is crucial Small cell power 50 mw to 5 Watts Macro cell power 40 Watts per antenna P-UE Further RF unbalance due to site height, antenna gain PeNB M - UE M - UE Interference mitigation at base station Interference Aware Scheduler Sub-band scheduling in frequency domain Resource partitioning in time domain P-UE M - UE M - UE M - UE Macro enb Advanced Receiver at terminal P-UE PeNB M - UE P-UE M - UE Macro enb Interference from PeNB Interference from MeNB Copyright 2011 Verizon, all rights reserved. Contents provided AS IS and subject to change without notice. Desirable PeNB signal Desirable MeNB signal 7

8 Increase Network Capacity Cell Range Expansion (CRE) Cell range expansion improves network utilization of high and lowpower nodes and provides flexibility on low-power node site selection Field trials demonstrated almost linearly gain of sector capacity as the number of small cell embedded increases Rel 8 UE cannot support larger than 6 db bias. UE with advanced receiver are needed 8, 6, 4, 2 db Homogenous Macro Setting Copyright 2011 Verizon, all rights reserved. Contents provided AS IS and subject to change without notice. 8

9 Served throughput (Mbps) Increase Network Capacity Example: Interference Mitigation and CRE Simulations demonstrated capacity gain from resource partitioning and interference cancellation Macro DL Served throughput vs. Edge UE throughput Macro UL radio frame Pico DL Pico UL Edge (5%tile) UE throughput (Mbps) Data served on subframe Data possibly served on subframe Data not served on subframe Copyright 2011 Verizon, all rights reserved. Contents provided AS IS and subject to change without notice. 9

10 Increase Network Capacity CoMP and Distributed Radio Access Network Tight coordinated CoMP with distributed MIMO in stadium and venue Centralized baseband bank with pooling gain Higher order spatial multiplexing and beam forming gain with distributed MIMO Tight coordinated multipoint Tx/Rx and joint processing Baseband Bank Challenging: high throughput and low latency backhaul between master BS and other BSs or radiating points Different Cell IDs Advanced DRAN with joint processing Same Cell IDs Copyright 2011 Verizon, all rights reserved. Contents provided AS IS and subject to change without notice. 10

11 Improve Network Mobility Mobility among small cells and macro cells are essential to ensure seamless user experience Cell radius reduced from few miles to few hundred feet Handover frequency increased as more small cells deployed Optimized handover and power control parameter/scheme to improve reliability and utilization Macro cells to/from small cells Small cell to small cell Macro to macro S E Copyright 2011 Verizon, all rights reserved. Contents provided AS IS and subject to change without notice. 11

12 UE s Role in Heterogeneous Network UE has played an important role in LTE network Provides channel state, precoding matrix and rank indications UE with poor antenna/rf design could have low MIMO, therefore, lower throughput UE is going to play even critical role in LTE-Adv Advanced receiver with interference canceller LTE-adv transmission mode to leverage spatial multiplexing: DL TM9, UL TM2 12

13 UE s Role in Heterogeneous Network Example: 700 MHz MIMO performance MIMO has provided a substantial performance improvement at 700 MHz [HR][urban] [NL] [HR] [urban] [L] 1 [FSR] [urban] [L] [FSR] [urban] [NL] Ref SP1 SP2 FP1 [HV] [urban] [L] [HR] [urban] [L] 1.4 [FSR] [urban] [L] [FSR] [urban] [NL] SP1 0.2 SP2 0 FP1 SINR (db) [HV] [urban] [NL] [HV] [urban] [NL] [HV] [urban] [L] Average rank two (MIMO) selection ratio Throughput normalized to reference antenna throughput Free space on roof (FSR), Hands in van (HV), Hands on roof (HR) in loaded (L) and unloaded (NL) network settings Ref: 2 pol-antenna with no limitation; SP1/SP2: Smart phone 3 x6, SP2 has high correlation. FP1: feature phone, 2.5 x4.5 13

14 Heterogeneous Network: Benefits and Challenges Hetnet will play an important role to address exponential traffic growth A high capacity, high scalability and cost effective solution Better throughput and consistent user experience Challenges High capacity backhaul Fiber availability and NLOS PTMP microwave solutions Engineering / site acquisition / zoning RF propagation and usage prediction tools for below the building clutter Network operation and management Macro and low-power nodes co-existence and optimization High performance devices Copyright 2011 Verizon, all rights reserved. Contents provided AS IS and subject to change without notice. 14