Open Base Station Architecture: Can Standardization enable true innovation ?

Christian Lanzani, Sr. Product ManagerRadiocomp ApS

Email: Christian.Lanzani@radiocomp.com

1Monday, October 13, 2008

Standardization to Kill Innovation ?

! Standardization helps commoditization of market product

! Brings many benefits for the customer or consumer

! Not so good for the profit margins of the suppliers

! Enable formation of supplier’s ecosystem

! Enable innovation to focus on solving customer needs

2Monday, October 13, 2008

Agenda

! BTS Standardization Goals

! OBSAI & CPRI Standards

! OBSAI RP3-01 vs. CPRI

! Air-Interface Profiles

! Radiocomp Case-Study

! Summary

3Monday, October 13, 2008

BTS Standardization Goals

! Reduce Costs (CAPEX/OPEX) & Time To Market.

! Hardware as a commodity.

! Innovative products and large selection through an ecosystem of suppliers.

! Reduce system integration efforts.

! Catalyst for partnerships models.

! Two major Open BTS architecture Initiatives:

OBSAI (Open Base Station Architecture Initiative)

CPRI (Common Public Radio Interface)

! Differentiation will be on Software Flexibility & Cost

4Monday, October 13, 2008

OBSAI & CPRI StandardsObjectives

! Define open, standardized internal modular BTS structure with specified form, fit and functions

! Define open & standards-based digital interfaces between modules

! Assure interoperability and compatibility between modules including test cases

! Define a set of standard OAM&P principles for integration of modules from multiple vendors

! Allow scalability for small to large capacity configurations and concurrent air-interface standards

! Active in supporting air-interface and vendor specific profiles

! OBSAI - Open Group started in 2002

! CPRI - Closed Group started in 2003

! Focus on Layer 1 and Layer 2

! Scope is restricted to the link interface only for P2P only

! Includes User Data, Control and Management Plane transport mechanisms and synchronization.

! OBSAI advantage is to support air-interface profiles

5Monday, October 13, 2008

OBSAI & CPRI StandardsRemote Radio Head Units

! RRHs advantages in DAS with BTS Multicast/Simulcast

Advantages of RRH:

! Higher power in the DL

! Better RF performance in the uplink

! Elimination of antenna cable

! Lowering of cooling reqmnts. & power consumption

! Higher reliability

! 1-BTS can serve multiple RRH in simulcast or in

Multicast fashion

! Applicable to DAS infrastructure to enable wireless

protocol upgrades leaving the hard access to

the equipment in place

Advantages of BTS Server:

!System Management

!Equipment upgrades

! The RRH concept allows separation of Base Band Processing from RF

6Monday, October 13, 2008

! Radio Heads are complex products

! Require very specialized technology and variants multitude

! Peak to Average Waveforms in 4G Technology conflict with……

! Low Power Consumption reqts. dictated by Backup Power Mandates & Cost of Energy

! Low Signal Distortion for High Spectral Efficiency

! Includes exotic high power semiconductors and advanced heat control

! Digital PreDistortion (DPD) & Crest Factor Reduction (CFR) techniques.

! High Flexibility required in operating multiple bands, standards & channels bandwidths.

! Low Footprint

! Low Cost. Low Cost. Low Cost. Low Cost. Low Cost ... and Low Cost.

! OEMs struggle to handle all RF variants internally

OBSAI & CPRI StandardsRemote Radio Head Units

7Monday, October 13, 2008

OBSAIReference Architecture

8Monday, October 13, 2008

OBSAI RP3-01Interface Overview

! RP3 Specification v.4.1

! Point-to-point serial interface up to 6.144 Gbps for Uplink/Downlink telecom Data, Control & Sync.

! Support all air-interface standards (GSM/EDGE, WCDMA/LTE, 802.16d-e,CDMA2000)

! The stack is based on a packet concept using a layered protocol with fixed length messages

! IQ Sample envelope size is fixed and defined from the air-interface used.

! RP3-01 has fixed Msg & sample envelope size

Data

Control

Sync

RP3 IQCarrier_1

RP3 IQCarrier_X

RP3 Ethernet10 / 100

RP3 Generic Ctrl Msg

RP1/RP3 Synchronized Ctrl Msg

Address TypeTime

Stamp

PAYLOAD (16bytes)

13bits 5bits 6bits

Message Group (M_MG=21 RP3 Messages)

RP3-01 Frame 10ms (i * 1920 Message Groups)

HEADER (3Bytes)

RP3 Message (19bytes)BTS

RP3-01 Optical Link

Digital I/Q

1 0 1

Tx / Rx

RRH

9Monday, October 13, 2008

CPRI InterfaceReference Architecture

! Includes User Data, Control and Management Plane and Synchronization transport mechanisms.

! A focus has been put on hardware dependent layers (Layer 1 and Layer 2)

! Ensures independent technology evolution with a limited need for hardware adaptation.

! Product differentiation in terms of functionality, management, and characteristics is not limited.

! Supports 3GPP UTRA FDD, WIMAX Forum Mobile System Profile v1.1.0 & LTE

! CPRI focus is on transport definition

10Monday, October 13, 2008

CPRI InterfaceInterface Overview

! CPRI Specification v.4.0 - Includes LTE & rates up to 3.072 Gbps

! User Plane Data with programmable IQ sample envelope size between 4 and 20bits

! C&M Channel Option 1: Slow C&M Channel based on HDLC

! C&M Channel Option 2: Fast C&M Channel based on Ethernet

! Vendor Specific Sub-channel / L1 Inband

! Synchronization word (K-char) and BFN, HFN Counters

! CPRI has programmable sample envelope size

Data

Control

Sync

Basic Frame

CPRI Frame 10ms (150 * 256 Basic Frames)

BTS

CPRI Optical Link

IQCarrier_1IQCarrier_X

Ethernet

HDLC

Sync

VSS / Alarms

Digital I/Q

1 0 1

Tx / Rx

RRH

11Monday, October 13, 2008

OBSAI RP3-01 vs. CPRILink Bandwidth Allocation

User Data (IQ) 80% 93.75%

Control Data (O&M) 4% 6.225%

Synchronization (K-char) 0.25% 0.025%

Fixed Overheads 15.75% 0%

! OBSAI RP3-01 ! CPRI

! A 3.072 Gbps link is assumed - Occupancy measured in bytes %

! OBSAI RP3-01 has higher overheads (+15.75%) for enabling flexibility

! CPRI capacity advantage (+13.75%) for optimized bandwidth allocation

! Tradeoff between capacity and flexibility

12Monday, October 13, 2008

OBSAI RP3-01 vs. CPRICarriers Capacity

AxC 3072 Gpbs AxC 6144 Gpbs AxC 3072 Gpbs AxC 6144 Gpbs

LTE 10 MHz @ 16bits samples 4 8 5 10

LTE 20 MHz @ 16bits samples 2 4 2 4

LTE 10 MHz @ 12bits samples 4 8 6 12

LTE 20 MHz @ 12bits samples 2 4 2 4

! OBSAI RP3-01 ! CPRI

! CPRI leverages on higher carrier grade capacity

! LTE carrier link capacity example

! CPRI has optimized sample envelope size => more carrier space

! OBSAI RP3-01 capacity is independant from sample envelope size

13Monday, October 13, 2008

OBSAI RP3-01 vs. CPRIFeatures Set

Physical Layer (L1)XAUI up to 6.144 Gbps XAUI up to 3.072 Gbps

8b10b coding / Scrambling (6G only) 8b10b coding

Data Link Layer (L2)

10ms Frames 10ms Frames

RP3 Frame = i,N_MG,M_MG,K_MG CPRI Frame = HF, BF, Word (Z.X.W)

Transport LayerRP3 Address Filtering

Vendor Specific

RP3 Type Filtering

Application Layer

RP1 M-Plane (XML / SOAP)

Vendor Specific

Index-Modulo/Dual BitMap Scheduling

RTT Measurements

RP1 Frame Clock Burst Synchronization

! OBSAI RP3-01 ! CPRI

! RP3-01 includes Transport / Application Layer definitions

14Monday, October 13, 2008

OBSAI RP3-01 vs. CPRIGeneral

Carriers Capacity Air-Interface Fixed IQ sample sizeAir-Interface Programmable IQ sample

size

RRH Network Design

RP3 Header easier Network configurationNetwork Configuration is Vendor

Specific

RP1 Frame Clock Burst & RTT Mechanisms

easier Network Synchronization and Calibration

System Synchronization is Vendor

Specific

Customization Efforts

RP3 Generic and Sync Control Msg

Interface Configuration

2 man/month

6-8 man/month

IQ Mapper / VSS / HDLC

O&M Integration EffortRP1 UDPCP/XML/SOAP

2-3 man/month

Vendor Specific

??? man/month

Applications

Balanced approach between Capacity/Flexibility

Indicated in complex RRH network topologies

More oriented toward INTEROPERABILITY

concept

Higher carrier capacity efficiency

Indicated for P2P High Capacity Links

More OPEN TRANSPORT oriented

! OBSAI RP3-01 ! CPRI

! OBSAI features enable simpler BTS configuration

15Monday, October 13, 2008

! Aiming at enabling true multi-vendor interoperability

! Inspired from WiMAX Forum activities on IEEE 802.16

! Air-Interface and/or Vendor Specific profiles

! Initially applied on RP3/RP3-01 interfaces

! Defining required set of options

! Defining required configuration set

! Defining generic system requirements and messaging formats

! Enabling OBSAI module vendors to lower integration efforts

OBSAI Air-Interface ProfilesScope

! Profiles will help the market players to move faster

16Monday, October 13, 2008

Radiocomp Case-Study

! Headquartered in Hillerød, Denmark

! Fully leveraging on products built around Open Standards

! Enabling OEMs to reduce cost & get faster to market

! Products Overview

! Soft Configurable Radio Heads for LTE and WiMAX

! Multi-Band Radios from 2.3 GHz to 3.8 GHz

! Low Footprint

! Market Reference for OBSAI & CPRI IP Cores

! Hardware reference platforms

! Consultancy services

17Monday, October 13, 2008

Summary

! OBSAI & CPRI are the most mature BTS standardization initiatives

! Radio Interfaces are similar but with different features set

! OBSAI better positioned toward multi-vendor interoperability

! Air-Interface Profiles will help to improve interoperability

! Standardization will allow innovation on features and performances

! OEMs will benefit of large suppliers selection & price/performance ratio

18Monday, October 13, 2008