embernet overview book 120 0001 210 - computer...

EmberNet Overview

120-0001-210 January 2003

C o m p a n y C o n f i d e n t i a l

Copyright © 2002 by Ember Corporation

All rights reserved

The information in this document is subject to change without notice. The statements, configurations, technical data,and recommendations in this document are believed to be accurate and reliable, but are presented without express orimplied warranty. Users must take full responsibility for their applications of any products specified in this document.The information in this document is the property of Ember Corporation.

EmberNet and Ember are a trademarks of Ember Corporation.All other trademarks are the property of their respective holders.


EmberNet Overview 120-0001

C o m p a n y C o n f

Contents

PrefaceAbout This Guide vAssociated EmberNet Documentation vGetting Help vi

CHAPTER 1 Introduction to EmberNetWhat Is EmberNet? 1-2Why Use EmberNet? 1-3

CHAPTER 2 How EmberNet WorksEmberNet Architecture 2-2

Embedded Network Infrastructure 2-2Comparison to Star Topology 2-4

Mesh Networking 2-6What an EmberNet Network Does 2-6Example of Mesh Networking 2-8

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Contents

CHAPTER 3 EmberNet Hardware and Software DescriptionEmberNet Node 3-2EmberNet Serial Node 3-3EmberNet Gateway 3-4EmberNet View 3-5Development Kit Models 3-8EmberNet Development Kit Tools 3-9

APPENDIX A Technical SpecificationsEmberNet Node Specifications A-2EmberNet Serial Node Specifications A-4EmberNet Gateway Specifications A-5

Index

iv EmberNet Overview 120-0001-210


Preface



About This GuideThis guide introduces you to the EmberNet™ product line for original equipment manufacturers.

Associated EmberNet Documentation

EmberNet Developer Kit User’s Guide

EmberNet Application Development Guide

EmberNet View User’s Guide

EmberNet Node Technical Specification

EmberNet Gateway Technical Specification

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Preface

vi

Getting Help

Documentation, customer service, and support are available at support.ember.com or by contacting your account representative at Ember.

EmberNet Overview 120-0001-210


http://support.ember.com

CHAPTER 1 Introduction to EmberNet



In This Chapter

About This Chapter

This chapter defines EmberNet and describes its benefits and features.

Topics

This chapter covers the following topics:

For this topic... See page...

What Is EmberNet? 1-2Why Use EmberNet? 1-3

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Introduction to EmberNet

1-2

What Is EmberNet?

A System Platform

EmberNet is a platform for wireless embedded networks. It allows original equip-ment manufacturers (OEMs) to produce intelligent systems of interactive sensing and control devices for a variety of automated applications, including building, industrial, and defense environments.

A Product Development Suite

EmberNet is a toolkit for developing custom applications of Ember Enabled devices. It includes a complete set of equipment for product programming, debugging, and integration. Ember provides all the hardware, software, training, and support services that application developers and system integrators need to ensure successful deployment of its patented technology.

A Technological Innovation

EmberNet is embedded networking, the underlying technology for connectivity between Ember Enabled devices. It is a model of networking designed to intercon-nect embedded microcontrollers using radio frequency (RF) communications based on IEEE standard 802.15.4 and Ember’s proprietary networking protocols.

With EmberNet, the networking system resides directly on each microcontroller itself, inside each device of the network. It is a system that takes up only a small portion of the circuitry and uses only low levels of resources for power and compu-tation. Each wireless device is preprogrammed to self-configure and communicate on demand in the network, creating an instant infrastructure that requires no pre-planning, fixed placement, or maintenance.

This combination of features in the EmberNet design leaves room for each custom device to perform its application tasks, and frees you to focus on developing appli-cations dedicated to solving problems for your customers.

120-0001-210 EmberNet Overview



Why Use EmberNet?


Why Use EmberNet?

The embedded wireless technology behind EmberNet makes it a cost-effective and practical platform to use for creating scalable data networks that are also flexible. As a tool, EmberNet is a quick and simple way to connect multiple components in a network. Table 1-1 lists and describes the distinguishing characteristics.

Table 1-1: EmberNet Features

EmberNet is... Because...

Easy to use • The programming interface for host applications uses a simplified set of commands that is com-mon across all EmberNet components.

• Ember Enabled devices are easy to set up. You just place them where you want them in the appli-cation environment.

Low cost • Wireless networking eliminates expensive wiring and personnel costs.

• Its peer-to-peer mesh architecture eliminates the need for a centralized access point or base station, reducing your capital investment.

Reliable • If one device goes down, its neighbor takes over. This occurrence is transparent, with no data lost.

• You can move devices to different locations or remove them altogether without disrupting net-work operations.

Adaptable • You can extend the network by adding more Ember Enabled devices, at will.

• It works in environments where TCP/IP and Ethernet networks are the tradition.

• Existing wired devices can become part of the wireless network.

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Introduction to EmberNet

1-4

CHAPTER 2 How EmberNet Works



In This Chapter

About This Chapter

This chapter describes the parts of Ember’s wireless networking architecture and what they do to form an EmberNet network.

Topics



EmberNet Architecture 2-2Mesh Networking 2-6

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How EmberNet Works

2-2

EmberNet Architecture

Embedded Network Infrastructure

An EmberNet network can contain from just a few to hundreds, thousands, or tens of thousands of nodes. Each node in the network is fully equipped for wireless communications to form an instant infrastructure.

With the networking mechanisms embedded into the nodes themselves, network management is transparent. You simply place the nodes in your application envi-ronment, where they need to be to perform their tasks in the system. Where you don’t have enough coverage for connectivity between nodes, you place a repeater to bridge the gap. When you want to extend the network, all you have to do is add more nodes.

Every node in the EmberNet network automatically recognizes its nearby neighbor nodes, connecting to form a complete communication path. This peer-to-peer archi-tecture establishes a self-organizing, decentralized network in the shape of a mesh.

Figure 2-1 illustrates the mesh-like structure of the EmberNet network. Table 2-1 defines the elements that represent the nodes in the network.

Figure 2-1: EmberNet Network Structure

Wireless connection

LAN

Workstation

EmberNetSerial Node

EmberNetGateway

EmberEnabledDevice

EmberNetNode






Table 2-1: EmberNet Elements

Item Element Description

Ember Enabled Device

Your custom device—a sensor or control mecha-nism and an embedded EmberNet Node, running the EmberNet protocol stack and your application code. Functions in the network with or without repeaters, serial nodes, and gateways.

EmberNet Node Repeater

Your equipment carrying the EmberNet Node alone for use as a repeater. Extends the network’s communication range and improves the reliability of its connectivity. Interoperates with all types of EmberNet elements.

EmberNet Gateway

Serves as a conduit between the wireless network and the TCP/IP Ethernet network. Provides remote monitoring and control services for all EmberNet elements. Multiple gateways allow you to:

• Make application or network data more broadly available outside the network.

• Logically connect physically separate networks.

Ember Enabled devices, repeaters, and serial nodes can use any EmberNet Gateway available in the network.

EmberNet Serial Node

Links a serial device, such as a PC for collecting application data, to the wireless network. Also replaces serial connections between devices, such as sensors and actuators in industrial applications, with a wireless link. Interoperates with all types of EmberNet elements.

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How EmberNet Works

2-4

Comparison to Star Topology

Traditional wireless systems follow the IEEE 802.11 standard for wireless local area networks (WLANs). These wireless systems implement a star network topol-ogy, which presents technological limitations that make them vulnerable to physi-cal obstructions, radio interference, single points of failure, and bottlenecks.

Ember’s implementation of mesh networking instead adopts the IEEE 802.15.4 standard for wireless personal area networks (WPANs). In accordance with this standard, EmberNet networks have a low bit rate, low power consumption, and low complexity. Devices in this type of network can interoperate over short distances in an unlicensed frequency band. With these attributes, the EmberNet mesh over-comes the limitations of the star network.

Figure 2-2 shows the differing structures of the mesh and star topologies. Table 2-2 outlines some characteristics that make mesh networking more robust, reliable, and secure.

Figure 2-2: Mesh Topology Versus Star Topology

Mesh Network Structure Star Network Structure






Table 2-2: Advantages of Mesh Networking

The EmberNet mesh has... A standard star network has...

• Flexible topologyYou can add, move, or remove nodes at any point in the network.

• Fixed topologyAll nodes are fixed to a central access point or base station.

• Decentralized control Every node can communicate with every other node in the network. If a node fails, data routes around it, and the network stays intact.

• Centralized controlNodes must pass data through the central station to communicate. If the central station fails, the whole network fails.

• Redundant, short pathsTraffic can flow over separate areas of the network, in parallel, and nodes can distribute applica-tion tasks. Reduced path length strengthens connectivity between nodes.

• Single, long pathsEach node has a dedicated path to the central station. Extended paths weaken connectivity. If a link fails, communication with the node is lost.

• Push technology supportMessages can be broadcast over the network when necessary, or unicast to a select node for effi-cient data flow.

• Pull technology relianceNodes must request data through the central station and wait for a response, which can slow the flow of data in the network.

• Efficient routingEach node serves as a router in the network, storing only as much information as needed to move messages quickly from source to destination.

• Costly routingThe central station routes all traffic, and must maintain exten-sive routing information about each node to move a message to its target.

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How EmberNet Works

2-6

Mesh Networking

What an EmberNet Network Does

Mesh networking supports the following key operating characteristics of an EmberNet network:

• Automatic Discovery. Ember’s patented networking algorithms and appli-cation layer interfaces enable nodes to discover each other without complex setup and configuration. The EmberNet host API allows for a messaging process in which nodes announce and request application services to learn about their location in the EmberNet mesh network.

• Self-Organizing. Each node directly communicates with its immediate neighbors. Out-of-range nodes communicate to each other by relaying mes-sages through intermediate nodes. All nodes cooperatively relay messages on behalf of their neighbors, forming complete communication paths.

• Dynamic Routing. A node in an EmberNet network does not single out a specific neighboring node to relay its message. Instead, it advertises its “cost” for delivering a message to a destination, and only nodes that can deliver at a lower cost, participate in relaying the message. This way, the message descends a loop-free gradient from the originator to the destination (Figure 2-3).

• Self-Healing. Multiple neighbor nodes have the capability to relay the mes-sages. Ember’s routing adapts well and maintains connectivity in frequently changing network topologies because it allows redundant paths. When each message reaches a number of nodes, a single link failure will not cause a break in the communication path, as long as another neighbor node relays the message.

In an EmberNet network, a packet is transmitted at the source node and travels downward toward the destination node, collecting and recording information from each node in its path, ending up taking the most efficient path (Figure 2-4).

To learn how to design your EmberNet application to make the best use of mesh networking, see the EmberNet Application Development Guide.




Mesh Networking


Figure 2-3: EmberNet Cost Gradient

Figure 2-4: Finding the Most Cost-Efficient Path

Source

Destination

Cost Gradient

Nodes

Source

Destination

Cost–Efficient PathRedundant Messages

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How EmberNet Works

2-8

Example of Mesh Networking

In a factory setting using Ember Enabled devices, the EmberNet protocols treat the radio network like a mesh. Each device recognizes nearby nodes, talks to them, and passes data along. Each node acts like a router. It figures out how to cost-effectively transmit data in the right direction.

In Figure 2-5, observe the start node and the destination node. Data cannot be transmitted through a cement wall. Instead, it takes a route around the concrete wall, thereby still able to reach its destination.

Figure 2-5: Ember Enabled Devices Routing Around a Barrier

Concretewall

LAN(Ethernet)

PC

EmberNetGateway

Startnode

Destinationnode

Wirelessconnection

Unsuccessful tries(cannot penetrateconcrete wall)

Successful tries(travels aroundconcrete wall toreach destination)



CHAPTER 3 EmberNet Hardware and Software Description



In This Chapter

About This Chapter

This chapter describes the hardware and software components that allow you to build an EmberNet network.

Topics



EmberNet Node 3-2EmberNet Serial Node 3-3EmberNet Gateway 3-4EmberNet View 3-5Development Kit Models 3-8

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EmberNet Hardware and Software Description

3-2

EmberNet Node

The EmberNet Node (Figure 3-1) is the primary building block for all elements in the EmberNet network. It is a small, wireless communications board designed to be embedded into a variety of OEM devices, or used as a repeater in the network. This peripheral module has a 2.2 inch by 1.5 inch footprint and uses common intercon-nects to accommodate integration with your customized carrier boards.

The EmberNet Node has an embedded network processor and a high-speed serial peripheral interface (SPI) for use with an external host processor. It uses a direct-sequence, spread-spectrum radio with 12 independent channels in the 900MHz band and multiple power modes. The module accepts an antenna in a screw-on form (low profile, medium height, or full height), or directly attached with a ground. For security, the EmberNet Node supports hardware-based encryption using the Advanced Encryption Standard (AES). For detailed specifications, see page A-2.

The EmberNet Node attaches to Ember’s breakout board for application develop-ment. It is also a component of the EmberNet Serial Node (page 3-3) and the EmberNet Gateway (page 3-4).

Figure 3-1: EmberNet Node (with Low-Profile Antenna)







The EmberNet Serial Node (Figure 3-2) is a prepackaged EmberNet Node (page 3-2) with a serial connector. It allows you to add wireless communications capability to existing equipment with serial interfaces. The EmberNet Serial Node comes standard with the most widely used industrial protocol, Modbus RTU, and supports other protocols with custom development or additional licensing. It inter-operates with all Ember Enabled devices, repeaters, and the EmberNet Gateway.

The compact enclosure contains the communications module premounted on a carrier board with a serial connector. It is available in two models: RS-232 and RS-485. The device includes a power supply adapter for connecting to a wall outlet, and a 900MHz, 1/4-wave, medium-height (3.46-inch) antenna. For detailed specifi-cations, see page A-4.

Figure 3-2: EmberNet Serial Node

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3-4

EmberNet Gateway

The EmberNet Gateway (Figure 3-3) interconnects the wireless EmberNet network and any TCP/IP Ethernet network, and provides user access to information about the network’s status and parameters through EmberNet View (page 3-5). It is a compact, factory-assembled device that contains the following components:

• An EmberNet Node (page 3-2) for communication within the wireless net-work

• An Ethernet port for a direct connection to a local or wide area network (LAN or WAN)

• A serial port for connecting a PC, workstation, or other serial device• A Linux-based, single-board computer (SBC) that runs Web, host API, and

network monitoring services

The EmberNet Gateway includes a power supply adapter for connecting to a wall outlet, and a 900MHz, 1/4-wave, medium-height (3.46-inch) antenna. For detailed specifications, see page A-5.

Figure 3-3: EmberNet Gateway




EmberNet View


EmberNet View

EmberNet View is a web-based application that runs on the EmberNet Gateway (page 3-4). With a standard Web browser, users can access the application remotely from their PC or workstation to monitor and configure all the nodes running in an EmberNet network. EmberNet View allows users to:

• Ping, reboot, and observe a status overview of all nodes (Figure 3-4).• Check the status of a specific node, review its error log, and edit its network

parameters (Figure 3-5).• Display a map of nodes that shows their location and connectivy in real time

(Figure 3-6).

Application developers can customize EmberNet View with a layout of the cus-tomer’s floorplan for the network map, and can use the application as a tool to debug their Ember Enabled devices. For more information, see the EmberNet View User’s Guide.

Figure 3-4: EmberNet View — Status Window

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Figure 3-5: EmberNet View — Node Detail Window




EmberNet View


Figure 3-6: EmberNet View — Network Map

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3-8

Development Kit Models

The EmberNet Developer Kit comes in several models that are outlined in the table below:

Table 3-1: EmberNet Developer Kits

Standard Advanced PremiumHardware 8 - EmberNet Nodes

8 - EmberNet Breakout Boards1 - EmberNet Gateway1 - USB Programmer1 - 6ft. Ethernet patch cable9 - 9V power supplies

12 - EmberNet Nodes12 - EmberNet Breakout Boards12 - EmberNet/Ethernet connection

boards1 - EmberNet Gateway1 - USB Programmer1 - 6ft. Ethernet patch cable13 - 9V power supplies

12 - EmberNet Nodes12 - EmberNet Breakout Boards12 - EmberNet/Ethernet connec-

tion boards1 - EmberNet Gateway1 - USB Programmer1 - 6ft. Ethernet patch cable13 - 9V power supplies

Software and Documenta-tion

1 - EmberNet Developer Kit CD1 - AVR-GCC 3.2.C Compiler

(Win 32)1 - EmberNet Node Binary1 - EmberNet Host API Specifi-

cations & Libraries1 - Sample Application1 - EmberNet View EmberNet Documentation

1 - EmberNet Developer Kit CD1 - AVR-GCC 3.2.C Compiler (Win

32)1 - EmberNet Node Binary1 - EmberNet Host API Specifica-

tions & Libraries1 - Sample Application1 - EmberNet View1 - EmberNet Simulator v1.0 (Linux)1 - EmberNet Node Binary for

EmberNet Simulator1 - EmberNet/Ethernet Debug Appli-

cation EmberNet Documentation

1 - EmberNet Developer Kit CD1 - AVR-GCC 3.2.C Compiler

(Win 32)1 - EmberNet Node Binary1 - EmberNet Host API Specifi-

cations & Libraries1 - Sample Application1 - EmberNet View1 - EmberNet Simulator v1.0

(Linux)1 - EmberNet Node Binary for

EmberNet Simulator1 - EmberNet/Ethernet Debug

Application EmberNet Documentation

Training and Support

1 year - Web based support only Annual Support1 - Training SeatTelephone, email and web support

Premium Support• 3 days - custom engineer-

ing(*T&E excluded)• 2 days (up to 5 students) -

Onsite training (*T&E excluded)

• Telephone, email and web support.

Optional Upgrades for additional fee

Discounted first seat training

Per incident support: • $750 per three incidents• First three incidents free upon

completion of training

EmberNet Debug Kit includes:8 - EmberNet/Ethernet Connec-

tion Boards1 - EmberNet Simulator1 - EmberNet/Ethernet Debug

applicationAdditional training seatsAnnual supportCustom engineering

• Additional Training seats• Custom Engineering

• Additional Training seats• Additional Custom Engi-

neering

* Travel and Entertainments




EmberNet Development Kit Tools


EmberNet Development Kit Tools

The EmberNet Development Kit is a collection of tools for the OEM application developer. The kit contains the following tools for building your own wireless net-work of Ember Enabled devices:

• EmberNet Nodes for developing a complete network of Ember Enabled devices

• EmberNet breakout board for each EmberNet Node under development with Rabbit Core Module boards for Ethernet debugging

• EmberNet Node binary files for running the EmberNet Protocol Stack• Host application programming interface (API) for creating your custom

application code• GCC compiler for compiling the application code • USB programmer for downloading your code to the host processor• EmberNet Debug Logging Utility for testing EmberNet nodes in a network

environment (not included in Standard Development Kit)• EmberNet Gateway and EmberNet View for monitoring connectivity in

the test network• Sample applications for viewing source code examples of EmberNet

applications• Documentation for guidelines on developing EmberNet applications

Developers using the Advanced and Premium EmberNet Development Kit also have access to extensive training and technical support at Ember (support.ember.com). Additional components, including the EmberNet Serial Node (page 3-3), are available on separate order. Contact your Ember account representa-tive. The kit supports but does not include an alternative compiler, the IAR Systems Embedded Workbench.

For more information about the kit contents and how to use them, refer to the EmberNet Developer Kit User’s Guide.

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http://support.ember.com


3-10

APPENDIX A Technical Specifications



In This Appendix

About This Appendix

This chapter lists the technical specifications for the main elements of the EmberNet network.

Topics



EmberNet Node Specifications A-2EmberNet Serial Node Specifications A-4EmberNet Gateway Specifications A-5

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Technical Specifications

A-2

EmberNet Node Specifications

Feature Specifications

Dimensions 1.5” x 2.2" x 0.3” (connectors exclusive)or 0.45 (connectors inclusive)

Operating Environment -30°C through +80°C

Power Requirements 3.5 to 5.0VDC

Microprocessor EmberNet 8-bit RISC processor

Interface Protocol EmberNet SPI (SPI and interrupt pin)

Interface Connections 32-pin and 24-pin, 2mm, off-center pin headers

I/O Connections RF: Reverse polar SMA connectorSPI: 2Mbps master/slave connection (EmberNet SPI)

Radio Direct sequence, spread spectrum

Frequency 902-928 MHz ISM band

Channels 12 2.048MHz wide channels

Channel Bit Rate 192Kbps

Transmit Power Adjustable: 0, +7, +14, +20dBm

Receive Sensitivity -95dBm

Range In open air, at full power, 1000ft line of sight with 1/4-wave antenna (extensible by EmberNet Node repeaters)

Antennas 1/4 wave, plastic whip RP-SMA 3.46” or direct attach with ground. The antenna must be installed in a vertical orientation.

Error detection CRC: CCITT16 and AES 128 CBC




EmberNet Node Specifications


Security Hardware-based Advanced Encryption Standard (AES 128-bit CCM)

Certification FCC Part 15 Modular Certified

Warranty 90-day, limited warranty


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A-4

EmberNet Serial Node Specifications


Dimensions 2.6” x 4.25” x 1.12” (without SMA connector)2.6” x 5.00” x 1.12” (with SMA connector)

Operating Environment -30°C through +80°C

Power Supply 9VDC

Host Microprocessor Atmel AVR (ATMega128L)

Protocols Modbus Serial RTU (standard)Other protocols available by custom development or additional licensing

I/O Connection RS-232 or RS-485

Radio Direct Sequence Spread Spectrum

Frequency 902-928MHz ISM band

Channels Twelve channels, 2.048MHz wide

Channel Bit Rate 192Kbps Effective throughput between two nodes in a single hop network as high as 50Kbps


Antenna 1/4 wave, plastic whip RP-SMA 3.46” or direct attach with ground. The antenna must be installed in a verti-cal orientation.


Certification FCC Part 15 Certified





EmberNet Gateway Specifications


EmberNet Gateway Specifications


Dimensions 6.3” x 5.1” x 2”

Operating environment -30°C through +80°C

Power 9VDC, 800mA

Processor StrongARM 1110, 192MHz

Operating System Intrynsyc Linux Distribution

Memory 16MB Flash, 32MB SDRAM, diskless

Serial Port DB9 connector

Ethernet Port 10BaseT

Indicators LEDs: Power, Ethernet, EmberNet, Application, Alarm

Software EmberNet Protocol Stack, EmberNet View, Apache HTTP Server


Antenna 1/4 wave, plastic whip RP-SMA 3.46” or direct attach with ground. The antenna must be installed in a verti-cal orientation.


Certification FCC Part 15 Certified


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A-6



Index

A

advantages of EmberNet 2-5architecture of EmberNet 2-2

C

components of EmberNet 2-3cost gradient 2-7

D

discovery 2-6documentation, related -v

E

EmberNet Developer Kit 3-8EmberNet Gateway

description 3-4function 2-3specifications A-5

EmberNet Nodedescription 3-2function 2-3specifications A-2

EmberNet Serial Nodedescription 3-3function 2-3specifications A-4

EmberNet View 3-5example, mesh networking 2-8

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Index

IX-2

F

features of EmberNet 1-3, 2-5

G

gradient, cost 2-7

H

hardware, EmberNet 3-2–3-4

I

IEEE 802.11 2-4IEEE 802.15.4 1-2, 2-4

M

map of EmberNet nodes 3-7mesh networking 2-6–2-8

N

network architecturecomparison to star networks 2-4components 2-3structure 2-2

node details 3-6node map 3-7node status 3-5

P

parameters of EmberNet nodes 3-6product description 1-2

R

related documentation -vrepeater 2-3, 3-2routing 2-6, 2-8

S

software, EmberNet 3-5specifications

EmberNet Gateway A-5EmberNet Node A-2EmberNet Serial Node A-4

status of EmberNet nodes 3-5structure, EmberNet 2-2support, technical -vi

T

technical support -vitopology

comparison to star 2-4EmberNet 2-2




EmberNet Overview120-0001-210January 2003

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embernet overview book 120 0001 210 - computer...

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