airspan: network densification using outdoor and indoor small cells

2015 Small Cells Forum AirRAN: The Virtual Small Cell Moti Bitter, VP Products, Airspan Networks

2 Copyright 2015 AIRSPAN NETWORKS INC.

AirRAN “Virtual” RAN

Next Generation Radio Access Network Architecture

•  Airspan Radio Access Network (AirRAN) •  Holistic Virtual RAN solution: V-RAN = Distributed RAN or Centralized RAN

•  same platform / same building blocks / same software… •  “Small Cell centric” Software Architecture portable and vendor independent

•  Uses Multi-core Network Processors (multi-vendor) •  For standalone MAC and V-RAN Blade Server

•  Several PHY interfaces from FAPI (aka nFAPI) to pure L1 PHY (I&Q) •  Designed to be easy to port to PHY Blade Server

PHY

MAC & L3

IP interface (nFAPI)

AirRAN eNodeBs can operate in one of three modes: 1.  Standalone: L1 PHY + L2/L3 MAC 2.  Local Cluster: L1 PHY on Clients, L2/L3 Master 3.  Centralised Cluster: Local L1 PHY


AirRAN Small Cell V-RAN Hardware Architecture

V-RAN Small Cells enable Standalone, Cluster and Centralized

Single eNodeB

Local V-RAN Clusters

Network Clusters

V-RAN Centralized Baseband Blade Server

Baseband “cost optimized” for for 1 or 2 carriers, or with higher cost for 3/4 carriers Multiple baseband options per product.

EPC, HSS, PCRF and IMS

S1 Interface

Master eNodeB has higher performance baseband (runs L2/L3 for cluster), L1 Clients regular basebands

L2/L3 Master L1 Client L1 Client

S1 Interface

L2/L3 Master

L1 Client L1 Client L1 Client

Remote clusters of eNodeBs running just L1 (PHY) hosted by centralized L2/L3

Baseband server

S1 Interface

#1

#2

#3


nFAPI: The Connectivity Advantage

•  2 CC CA LTE Configuration: TDD with 2x20 MHz CA, FC-2, SSF7

nFAPI requires 20 times less front-haul bandwidth And works with 8 times higher latency

when comparing with CPRI C-RAN

2x2 running 2x20 MHz CA CPRI nFAPI Fiber / Ethernet Rate 10 Gbps 1 Gbps Payload Rate ~6 Gbps ~0.3 Gbps Latency Up to 250us ≤ 2 ms Centralized-Pool HW Dedicated DSP General Num. of cells per Fiber ring (10 Gbps) 1 ~15-30

R-Units per blade 3-6 ~8-16 / 4

* Future - eCoMP


•  Adding street pole mounted Small Cells as a 2nd LTE layer for the Macro deployment in a dense urban area – Akihabara “Electric Town” Tokyo

•  using Smart Omni Antennas

2015 SoftBank Trial – Akihabara ,Tokyo

Many thanks to SoftBank for allowing us to share some of the results!


Outdoor Coverage No Load •  Small Cells improves Throughput over Macro only

•  Directional is slightly better than Omni

Outdoor Tests – CDF

27

41 43

Main Streets

Main Streets Avg. Throughput

Macro Only

Macro + Small Cells Omni

Macro + Small Cells Directional

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 96 101 106

CDF

Throughput [Mbps]

Main Inner Streets Throughput CDF

All SCs Omni With MCs

All SCs Direc>onal With MCs

Macro Only


The Impact of V-RAN Small Cells: Outdoor

•  Based on Outdoor Drive Tests •  Note: Macro cells have 26% no coverage

•  Dedicated channel utilizing 40 MHz

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110

CDF

Throughput [Mbps]

Drive Test Data (100% load)

Dedicated Channel 100% Load CoMP ON

Dedicated Channel 100% Load CoMP OFF

Macro Only 100% Load

No eICIC


The Impact of V-RAN Small Cells: Outdoor

•  Based on Outdoor Drive Tests •  Note: Macro cells have 26% no coverage

•  Co-channel utilizing 20 MHz

•  CoMP improves the results by 380% for Co-Channel

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110

CDF

Throughput [Mbps]

Drive Test Data (100% load)

Co Channel 100% Load CoMP ON

Co Channel 100% Load CoMP OFF

Macro Only 100% Load

No eICIC


The Impact of V-RAN Small Cells: Network Capacity

0

50

100

150

200

250

300

350

400

450

500

Macro Only Dedicated Channel Co-Channel Co-Channel w.eICIC

293

379 435

304

408 461

109

Network Aggregated Capacity (Mbps)

No CoMP (3GPP CoMP) Macro Only

•  Tested across the full area •  400% higher capacity compared to Macro only

by using V-RAN Small Cells with CoMP and eICIC

x4


The Impact of V-RAN Small Cells: Indoor

•  Indoor shows 600% gain compared to Macro only; and (50-100)% compared to Macro + Small Cells (without CoMP)

5.1 12.1 10.2 8.8

29.7 36 35.1 34.6

75.2 72.7

62.3

48.7

1 2 3 4

Indoor Throughput Gain [Mbps]

Macros Only Macros + Small Cells CoMP ON

x6 4

3 1

2


Conclusions – The value of nFAPI V-RAN Small Cells

•  Rooftop Macro Cells cannot provide an adequate capacity or coverage

•  In high frequency bands like 2.5 GHz and 3.5 GHz •  After model tuning Coverage and Capacity can be accurately predicted

•  Heterogeneous Networks are the solution to Dense Urban Networks

•  An underlay of Small Cells can complete the required coverage at street level and indoor locations even in higher frequency bands:

•  Small Cell can be used for coverage infill purposes in areas where macro cell layer signal is too low

•  Small Cells densification increase network capacity, especially in hot spot locations.

•  Small Cell gain compared to Macro only presented almost 400% outdoor gain and ~400% indoor gain

•  Heterogeneous Networks Preferred Approach: •  Shared Channel approach should be preferred. It appears that the wider spectrum

availability of the shared channel approach outperforms its higher interference level


Conclusions – The value of nFAPI V-RAN Small Cells

•  Intra Small Cell Layer Interference Mitigation – CoMP •  CoMP proved to be a very effective solution for interference mitigation between Small

Cells •  CoMP Aggregate Capacity Gain in Outdoor Locations observed:

•  400% compared to Macro •  Outdoor Cell Edge CoMP Gain observed: 250% compared to Small Cells with no CoMP •  CoMP Indoor Gain observed:

•  600% compared to Macro

•  Centralized CoMP: •  Centralized CoMP based on pooling L2 processing and distributed L1 processing

proved to be as efficient as pooling L1 and L2 processing using CPRI fronthaul interface

•  Inter Small Cell – Macro Interference Mitigation – eICIC •  Time Domain eICIC is an effective way to mitigate interference between small cell

layer and macro cell layer. •  The results indicated a potential gain of eICIC in both average capacity (15%) and

cell edge performance (45%)


AirRAN: Airspan’s Virtual Small Cell

2015 Winners

airspan: network densification using outdoor and indoor small cells

Technology