Standards Development and Convergence Skip Ashton Senior VP Engineering Ember Corporation.

Standards Development and Convergence

Skip AshtonSenior VP Engineering

Ember Corporation

Overview• ZigBee Standards Development Process• What takes the time and effort?

– Questions and issues in standard

• Where is it converging?

Application Profiles(defined by ZigBee and OEMs)

Stack Feature Sets(defined by ZigBee)

Radios(defined by IEEE 802.15.4)

ZDO

NWKNWK

App Support (APS)App Support (APS)

SSPSSP

ZigBee Systems Architecture

Physical Radio (PHY)Physical Radio (PHY)

Medium Access (MAC)Medium Access (MAC)IEEE 802.15.4 Ratified 2003, Updated 2006

ZigBee 2007 Specification: - ZigBee PRO

Home Automation (HA)Building Automation (CBA)Smart Energy (SE)+ more ...

CustomOEM…

CustomOEM…HCLHCL

ZDO

NWKNWK

App Support (APS)App Support (APS)

SSPSSP

CustomOEM…

CustomOEM…HCLHCL Custom

OEM…CustomOEM…

AppProfileApp

ProfileZDO

NWKNWK

App Support (APS)App Support (APS)

SSPSSP

Who is Involved in ZigBee?• ZigBee Promoters represent cross section of

providers and users of technology– Ember, Emerson, Freescale, Itron, Landis & Gyr,

Philips, Reliant Energy, Schneider, ST, Tendril and Texas Instruments

• Membership over 300 additional companies

ZigBee Development Process• Marketing Working Group – defines features required and

creates MRD• Architecture Review – Reviews MRD and assigns to Work

Group for Completion• Work Groups – Complete specific assigned work to create TRD

and then Specification– Core Stack – Ongoing stack maintenance and Cluster Library– Home Automation– Smart Energy– Commercial Building Automation

• ZigBee Qualification Group – test plan development and testing to validate specifications

Smart Energy Development Timeline

• December 2006 Marketing Study group formed• MRD Ballot March 12, 2007• TRD Ballot Nov 14, 2007 • Initial Pretest event Dec 7, 2007• Profile Approved by Board (Rev 14) in June 2008• Vendor release of product – 3-6 months later• ~18 months to complete then time for vendor to

release– 3 months MRD, 8 months TRD, 5 months testing, 3-6 months for

product release

What takes the time?• Bulk of time is in technical development and testing

(13 of 16 months)– Define specific devices needed– Define attributes and commands for each device (data types,

sizes, optional fields etc)– Define message formats and exchanges– Define device behavior based on messages

• Only as required – do not test functional behavior but required device behavior from commands

• Testing defines if this is done properly, use or error cases covered, can be properly implemented

Beyond Devices and Clusters

• Application profile must also specify underlying network behavior, policies and security

• Baseline ZigBee provides underlying wireless technology for:– Forming and joining networks– Security– Network routing and management– Application service discovery– Error handling and recovery

• It is not enough to define data models and commands – network must operate under known conditions– No different than what happens when you arrive to use a strange WiFi

access point

What else is developed?• Developing the standard is not enough• Work group also developed a test plan to certify

devices as compliant and interoperable– Test events held from December to May– Validate specification and test plan– In final event certify those devices that complete testing– Also validate test harnesses used by ZigBee test houses for

certification of additional devices

How Does this Converge?• Many Groups Defining Data Types and Models

for various Smart Grid Elements• Data can be represented in various formats

– ZigBee uses binary messaging for efficiency on low bandwidth wireless communications

– IEC specifies object models in CIM using XML – OASIS also defines models in XML

Data versus Behavior• Mapping of data between different models generally not

difficult– SE 1.0 was mapped to CIM– SE 2.0 evaluating tokenized XML for data format

• Different mappings or data formatting will converge over time

• This data mapping is small part of overall specification– Network behavior and security– Commands and expected responses– Device behavior – normal and error cases– Testing to validate behavior and interoperability

Specification Efforts• Many groups now wanting to write pieces of the

specifications• ZigBee is moving the opposite direction and working

to harmonize– Already working with IEEE on PHY/MAC– Moving to IETF based routing methods, security etc– Contributing Application Profile to IEC to commonize models

and methods

• In the end the market wants unified standard solutions and not arguments on whose is better