© 2008 IBM Corporation ZigBee Range Extenders

© 2008 IBM Corporation Zigbee Range Extenders 2 Generic Term being used by Vendors to describe devices that extend a 2.4 GHz Zigbee signal around obstacles or to large distances– (based on RF characteristics) Some vendors are interchanging the term Extender with repeater, router, relay – depending on their architecture Two connectivity characteristics: 1. Extenders that are unsecured and whose function is to extend the broadcast range between one ESI and secured devices. Typically do not have any logical functionality built into them and thus no connectivity details. These type of extenders provide neutral signal amplification between an ESI and HAN device(s) and will not occupy a HAN device allocation slot provide by a utility ESI. It provides “open” communication support. 1b. Extenders that are unsecured and whose function is to extend the broadcast range between multiple ESI’s and multiple secured devices. All other characteristics are the same as Number 1 above. 2. Extenders that are secured whose function is to extend the broadcast range between two secured devices. Extenders that require a secured trust link between an ESI and a HAN device. These type of extenders will occupy a HAN device slot provided by the utility ESI. Typically single network specific (other networks’ devices can’t hop through) Note: Vendors development focus seems to be in this group. Note: A wireless range extender works as a relay or network repeater, picking up and reflecting WiFi signals from a networks access point. The Network performance of devices connected through a range extender will generally be lower than if they were connected directed to the AP.

© 2008 IBM Corporation Zigbee Extender Characteristics - Technical ScenarioNon Secure Extender supporting one ESI to Device(s) Non Secure Extender supporting Multiple ESI to multiple Devices Secure Extender supporting One ESI to Device(s) Secure Extender supporting Multiple ESI to Devices(s) RangeFollow Standard. Range degrades with more hops. Varies with environment and positioning N/AFollow Standard. Range degrades with more hops. Varies with environment and positioning N/A ESI Slots OccupiedNoN/A (Probably not)Yes. More if driven by a one to one relationship between device and extender and ESI. Yes Power120VAC or batteryN/A (Probably 120VAC or battery) 120VAC or batteryN/A (probably 120VAC or battery) SEP 1.0/2.0 Considerations None Ideally a secure packet passthru Yes Ideally a secure packet passthru Yes Device CostN/A - $$ Key Pro’s vs Con’sPro’s No ESI Slots Con’s No Security More devices installed – 1T1 Pro’s No ESI slots Less devices installed Con’s N/A Pro’s Security Con’s ESI Slots used More devices installed – 1T1 Pro’s Security Con’s ESI Slots used CommentsDevice payload remains secure. Multiple ESI’s in one network is the limitation. Monitoring SEP 2.0 developments Device payload remains secure. One extender per device. Multiple ESI’s in one network is the limitation. Monitoring SEP 2.0 developments. Who’s ESI to connect to? Market AvailabilityNo.Vendors willing to work with TDSP’s. Need development dollars. Yes. Manufacturer specific.Vendors willing to work with TDSP’s. Need development dollars. 3

© 2008 IBM Corporation Responsibility Matrix QuestionsTDSPREPComment Demarcation PointWhere is the ownership demarcation point? For TDSP, demarcation point of ownership is the meter ESI. Own the Line Side. REP owns the consumer.REP’s and TDSP to continue working together to solution Installation LocationsWho owns the physical location of installation? Who negotiates installation access? Who maintains access rights for maintenance? How many devices need to be installed and are they unique by manufacturer? Vendor ideal location varies – does TDSP have space in location? On poles or secondaries – do devices meet Pole installation specs? Do devices meet NEMA Specs? Every premise is an engineering study (Vendor specific) Any ongoing liabilities? Who installs the device in the premise (power, construction, access)? Ongoing liabilities? Every premise is an engineering study (Vendor specific) A MDU has multiple meters with potentially multiple REPs. Power RequirementsWhat is the battery life? Who maintains device? Who supplies Electric power? Who pays for ongoing power What is the battery life – based on location Life cycle of device management (power thresholds) Consumer maintenance?Offer extenders as part of programs (WiFi) or mass merchandising (WiFi). Support DesksWho provides support desk activities, trouble tickets, etc? Who makes decision on problem issue? Can a device failure be remotely determined? Multitude of devices means multitude of complexities – interoperability Maintenance and truck roll expectations. Multitude of devices means multitude of complexities 4

© 2008 IBM Corporation Texas HAN Requirements BR-025 – Cancelled – Not Needed Ability to provision a HAN device to more than 1 ESI at a time, unless the TDSP precludes this from happening. SEP 1.0 – Only one device to one ESI at a time. SEP 2.0 – Multi-ESI in discussion only. Not approved and no development being done.

© 2008 IBM Corporation Zigbee Extender Options OptionsPro’sCon’s ESI Zigbee to WiFI/WiMAX convertersVaries by vendor WiFI has longer range than Zigbee, higher throughput A little more flexibility in installations Varies by vendor Same installation issues as Zigbee Extenders ESI Zigbee to PLC/BPL conversionsDeep penetration in premises Full coverage of premise through electric lines Another piece of hardware near meter banks – transceiver in TDSP space More hardware in consumer premise Same installation issues as Zigbee Extenders BroadbandRicher functionality - gateways Rely on building wiring/wireless Telco provides support for broadband Broadband penetration rate (60-65%) in Texas – low income may be lower No near real time access to meter HAN device cost higher (probably using a gateway) Wideband - Paging/Cell (Blackberry, IPhone), etc Telco partnershipsMore hardware at meter banks Research and development cycle OtherTBD 6

© 2008 IBM Corporation Sample Zigbee Range Extender Devices 7 Battery PoweredTendril Extender - Plug-in Note: Product development Costs – Many vendors have asked for development dollars and partnerships to help develop solutions in this space