Enea Linux Base Station

Platform

Conny Öhult – Director Mobile Network Solutions, CTO Team

2012-08-14

Mobile Device Internet Usage is Picking Up!

50% covered by LTE 2017

60% of traffic from metro & urban 2017

Global mobile traffic 2010-2017 Global mobile traffic 2010-2017

15x growth driven mainly by video. Smartphone 1GB per month

Mobile PC 8GB per month

Source: Ericsson Market & Traffic Report June 2012

Multi standard Radio Access Networks

Next generation Antenna Integrated Radio Unit

Source: 4G Americas, ALU, NSN, Ericsson, Verizon

Iub

Iub

S1-M

ME

S1-U

Different standards are consolidated into one base station

OSS

Converged multi standard macro base stations and small cells (micro main-remote, and pico)

Wi-Fi

LTE Evolved UMTS Terrestrial Radio

Access Network (EUTRAN)

Layer 2-3

Can be implemented in a

communication processor

Layer 2 is often implemented

together with L1 in the DSP to

reduce the latency of the MAC

and L1 interaction

Layer 1 or Physical Layer

(PHY)

Usually implemented in a DSP

X2AP XP Application Protocol

RRC Radio Resource Control

GTP-U GPRS Tunnelling Protocol - User plane

SCTP Stream Control Transmission Protocol

S1AP S1 Application Protocol

UDP

Secure IP

PDCP Packet Data Convergence Protocol

RLC Radio Link Control

MAC Medium Access Control

O&

M

SO

N

Self-O

rganiz

ing N

etw

ork

s

RR

M

Radio

Resourc

e M

anagem

ent

Bit Rate Processing

Symbol Rate Processing

iFFT inverse Fast Fourier Transform

FFT Fast Fourier Transform

Ctrl plane

to/from MME

(S1-MME)

Ctrl plane

to/from

eNB (X2-C)

Data plane

from SGW or

eNB (S1-U/X2-U)

Data plane

to SGW or

eNB (S1-U/X2-U)

From

Antenna / UE

To

Antenna / UE

EUTRAN Layer 1

EUTRAN Layer 2

EUTRAN Layer 3

Internet Layers

eNB Application

Specific Software

Source: Enea

Operation and

Support System

- OSS (Mul)

A Variety of SoC Implementations

Multi-chip with different sRIO types or SoC or a mix

Linux, Hypervisor and/or RTOS, and a DSP RTOS

Macro, small cell, public safety

Enea Linux Base Station Platform Layer 2-3

Enea Linux

Enea LWRT

Enea Hypervisor

Enea OSE

Enea Linux Base

Station Platform

LTE Layer 2 & 3

MME

SGW

Other eNB

OSS

LTE Layer 1

PHY

Enea Base Station DSP Platform Overview

Enea Linux

Enea LWRT

Enea Hypervisor

Enea OSE

Enea Base Station

DSP Platform

LTE Layer 1 (& 2)

Enea Proprietary and Confidential

What does the SW Developer Want? Platform Team or LTE Application Developer

Performance – Latency and

Throughput

Shorten time-to-market.

- I.e. not be the red flashing box in

the integration tree preventing the

first call

Solve issues quickly

- I.e. not be the flashing red box in

the verification matrix

Portability/Scalability to future HW.

Protect existing SW investment.

Dream and Reality

The software developer wants:

A homogeneous Linux based SW environment

Port L2 to Linux

Effiective communication

Backward compatibility with existing code base

Hardware might provide:

Heterogeneous architectures

Assymetric/non-uniform & incoherent memory

Linux provide:

Poor real-time performance

IP, IPC and L2-L1 communication performance under utilizing

HW

LTE Layer 2&3 Platform Overview

Operating System

IPC and System & DSP

Management Middleware

IP Transport LTE Layer 2

LTE Layer 3

eNB Application Specific

Enea Linux

Enea LWRT

Enea Hypervisor

Enea OSE

Enea Linux

Enea LWRT

Enea Hypervisor

Enea OSE

En

ea

PA

X

Enea Element – dSPEED – LINX

GT

P-U

PD

CP

RL

C

MA

C

SC

TP

X2

AP

S1

AP

RRC

O&M

SON RRM

Enea L

INX

MME

SGW

Other eNB

OSS

LTE Layer 1

PHY

Mulicore SoC – E.g. B4860,

T4240, …

Layer 1 Platform Overview

Operating System

IPC and DSP

Management Middleware

LTE Layer 1 – E.g. Freescale L1 implementation

Enea Linux

Enea LWRT

Enea Hypervisor

Enea OSE

Enea OSEck

Enea

LIN

X

Enea dSPEED – LINX

Bit R

ate

Pro

ce

ssin

g

Sym

bo

l R

ate

Pro

ce

ssin

g

FF

T / iF

FT

Enea L

INX

LTE

Layer 2

Radio Unit

Antenna

Mulicore SoC – E.g. MSC8157, B4860, BSC9132 …

MME

SGW

Other eNB

OSS

LTE Layer 1&2 DSP OS Solution Overview

Operating System

IPC

LTE Layer 1 & 2

Enea Linux

Enea LWRT

Enea Hypervisor

Enea OSE

Enea OSEck

Enea L

INX

& P

FL

Enea LINX

Enea L

INX

LTE

Layer 3

Radio Unit

Antenna

E.g. MSC8157 Mulicore DSP

GT

P-U

PD

CP

RL

C

MA

C

Bit R

ate

Pro

ce

ssin

g

Sym

bo

l R

ate

Pro

ce

ssin

g

FF

T / iF

FT

Ethernet

sRIO

Enea Proprietary and Confidential

Power Archtecture CPU core(s) StarCore Multicore DSP Domain(s) Power Architecture CPU core(s) Starcore Multicore DSP Domain(s)

LTE and HSPA+ PHY Layer 1 (& 2)

OSEck 5

Enea’s Linux Base Station Platform In the Context of the Hardware and Enea Products

LTE and HSPA+ Layer 2 & 3

Enea Linux

LWRT / Hypervisor / OSE

PAX + LINX Shared Memory / Ethernet / sRIO

dSPEED PHY management / control

LINX

Shmem or DMA

RTOS optimized for DSPs

Linux + real time characteristics

Inter-process communications

service across all layers

Runtime layer adaptable to any board setup

DSP management / control platform

System wide tools

CLI tools and Optima Eclipse

Backplane/LINX Shared Memory/DMA/…

IP transport optimized for hardware acceleration

Radio Unit

Antenna

MME

SGW

Other eNB

OSS

Source: Enea

Element Application Developement

Services

System management middleware

Bit Rate Processing

Symbol Rate Processing

iFFT inverse Fast Fourier Transform

FFT Fast Fourier Transform

X2AP XP Application Protocol

RRC Radio Resource Control

S1AP S1 Application Protocol

PDCP Packet Data Convergence Protocol

RLC Radio Link Control

MAC Medium Access Control

O&

M

SO

N

Self-O

rganiz

ing N

etw

ork

s

RR

M

Radio

Resourc

e M

anagem

ent

Enea Element Enea dSPEED

Enea PAX Enea LINX

Enea Linux

Enea LWRT

Enea Hypervisor

Enea OSE

Enea OSEck 5

Enea LINX Enea LINX Enea OSEck Backplane

Enea Optima

Linux with Real-Time Characteristics Options

OSE Linux + Hypervisor

Linux + LWRT Linux

Bill of Material Cost Fewer cores /CPU cycles needed by

the application

Source: Enea

Note: Figures are not exact. This picture illustrates how lower and more deterministic task

switching and interrupt latency time can contribute to cost-effective CPU utilization by for example

using fewer cycles and avoid dedicating CPU cores to only perform certain latency sensitive tasks

Light-Weight Runtime Environment (LWRT)

Pthread

Linux Kernel

Pthread

LWRT Environment

LWRT Kernel

Module

Realtime Processes Non-realtime Processes

LWRT partitions the system into one realtime domain

and one non-realtime domain.

LWRT adds a user-mode runtime environment,

including an optimized user-mode scheduler.

LWRT migrates some specific kernel functionality (e.g.

timers) away from the realtime domain.

LWRT adds a kernel module to catch and forward

interrupts to the user-mode environment.

Core

0

Core

N

Linux Kernel

LWRT way: We can simply avoid using

kernel functionality in situations that causes

realtime problems:

Linux Kernel

Enea LWRT vs. PREEMPT_RT:

PREEMPT_RT way: We rework the internals of

Linux:

User Mode Runtime

We can partition a single Linux instance and separate

realtime from non-realtime.

We can configure processes and interrupts to run with

core affinity.

We make minor modifications to the kernel to avoid

running kernel threads/timers on realtime cores.

We can avoid using/calling the kernel, and rely on user-

mode functionality instead.

Require significant changes compared to “standard” Linux.

Taking 3.0.27 as an example, PREEMPT_RT patches

500+ locations in the kernel, with 11,500+ new lines of

code in total.

Linux User Space

Component

Linux Kernel

LWRT show very good realtime

characteristics with an almost

unmodified kernel.

Linux Kernel

Enea Can Support Both Options Separate or Together Complementing Each Other:

We can offer PREEMPT_RT as

part of Enea Linux:

LWRT

LWRT doesn’t exclude PREEMPT_RT. These technologies are not necessarily competing, but can actually be used in

combination. E.g. if low latency is required on Core 0 but best possible latency performance is needed on Core 1.

However an LWRT solution achieve best results without PREEMPT_RT present, but still provide great latency

improvements even when PREEMPT_RT is enabled.

Linux Kernel

LWRT and PREEMPT_RT can

coexist:

LWRT

Enea PAX IP Transport for Base Stations

1. A Foundation for Achieving High Performance IP Transport

2. PAX Provide a Multicore Dynamically Scalable IP Transport

3. PAX Architecture Help Minimize Power Consumption

4. A Foundation for Accelerating IP Transport Implementations

5. PAX Help Application Developers Find and Resolve Issues

Quickly

6. PAX can be Reused in Future Projects

PAX Overview – LTE Layer 2 Example

Linux operating system

Enea Packet Acceleration

Foundation (PAX)

LTE Layer 2 processing

Ethernet

Enea Linux

Enea LWRT

Enea Hypervisor

Enea OSE

sRIO or

Shared Memory

SGW

Other eNB

LTE Layer 1

PHY

Linux or OSE RTOS Kernel

User Space HW Access

Core 1 Core 2 Core 3 Core4 Core 0

Enea PAX

O&M

Control

Signaling

GTP-U

Termination

&

PDCP

Processing

GTP-U

Termination

&

PDCP

Processing

RLC & MAC

Processing

RLC & MAC

Processing

Slowpath Partition Fastpath Partition Realtime Partition

HW acceleration &

peripheral access from

Linux User Space

Std

So

cke

ts

AP

I

Std

So

cke

ts

AP

I

PA

X

Sp

ecific

AP

I

Std

So

cke

ts

AP

I

PA

X

Sp

ecific

AP

I

Std

So

cke

ts

AP

I

Dri

ve

r

AP

I

Std

So

cke

ts

AP

I

Dri

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r

AP

I

Mulicore SoC

Periodic, driven by

interrupts and timeouts,

multiple processes,

optimized for low

latency and context

switch overhead

Aperiodic, driven by

ingress/egress packets,

single-threaded run-to-

completion, optimized for

throughput and low per-

packet overhead

Legacy/slowpath IP stack

O&M appplications

SCTP termination and

control signalling

(maybe split this is one

partition for

slowpath/O&M and one

partition for SCTP/control)

LTE Layer 3 Control

Signaling and O&M

Enea LINX IPC for Base Stations

Enea’s solution for distributed IPC.

A protocol stack for asynchronous

message-passing between

processes/threads, cores, and

processors in a distributed system.

An open protocol (Linux core

implementation available under

GPL license).

Location transparent – intra-core

and inter-core communication done

in the exact same way.

Media independent.

LINX messages/signals can carry

data of almost arbitrary size.

Good fit for L3, L3<->L2, and

L3/RRM<->Radio control

communication

RLNH

CM

IPC

liblinx User

space

Kernel

space

RLNH

CM

IPC

liblinx

MEDIA

RLNH

protocol

CM

protocol

Enea Confidential

LINX Overview

OSE API LINX-for-Linux API

Management Interfaces Traffic Interfaces

Management Tools/API

Connection Manager (CM) Traffic and Management Interfaces

Address Resolution Link Supervision Link Management

Reliable Media

E.g. sRIO Type 11 & 9

Unreliable Media

E.g. Ethernet

Direct Memory Access

E.g. Shared Memory,

sRIO Type 5

Fragmentation Fragmentation

Sequencing

Retransmission

Session Layer

The RLNH Protocol

Transport Layer

Connection Manager Protocols

(Link Dependent)

Low Level Driver Layer

Enea Proprietary and Confidential

LTE/HSPA Picocell Board

BSC9132 SoC

A Picocell Example 2012

Linux CLI tools and OSEck Shell

Optima Eclipse

LINX over Shared Memory & DMA

dSPEED

OSEck

DSP C0

dSPEED

OSEck

DSP C1

Ethernet

IP and LINX

over Ethernet

Linux

C0

dSPEED

Linux

C1 IP Transport optimized for HW acceleration Ethernet / IP connection for Tools

Multi channel LINX / OSEck Backplane

core-to-core communication

System wide tools covering SoC

Enea Linux tailored for the base station use-case Enhanced with a light weight run-time

An

ten

na

To SGW / MME / eNB / RNC / OSS

DSP management over shared memory

Source: Enea

LTE/HSPA Macro Base Station Board

B4860 SoC

An Multi-Standard Macrocell Example 2012

Linux CLI tools and OSEck Shell

Optima Eclipse

LINX over Shared Memory & DMA

dSPEED

OSEck

DSP C0

dSPEED

OSEck

DSP C1

dSPEED

OSEck

DSP C5

Ethernet

IP and LINX

over Ethernet

Linux

C1

Linux

C0

dSPEED

Linux

C3

Multi channel LINX / OSEck Backplane

core-to-core communication

System wide tools covering SoC

LINX HDLC communication

IP Transport optimized for HW acceleration Ethernet / IP connection for Tools

Enea Linux tailored for the base station use-case Enhanced with a light weight run-time

DSP management over shared memory

To SGW / MME / eNB / RNC / OSS

Remote Radio Unit

Basic Enea Linux

Source: Enea

Thank You! – Questions?