1. Mode 2 Revision to ISO 18000-7
DASH7 Alliance
20 July 2010
Copyright © DASH7 Alliance

2. Motivations, and New Ideas
• Members of the DASH7 Alliance began, in February 2009,
coming up with must-have feature upgrades for ISO
18000-7. These revisions, it has been deemed, are Features Made Possible
absolutely required to advance the adoption of ISO 18000-7 • Decreased device size (SoC’s, smaller batteries)
into markets that are served by similar, proprietary
• External communication events (sensor alarms,
technologies concurrently developed by these DASH7 passive RF integration)
Alliance members.
• Amorphous networks (lots of unstructured
‣ Improvements to PHY in order to improve performance and decrease mobile readers, fixed and mobile tags)
cost in modern silicon implementations
‣ Improvements to MAC for greater channel efficiency (i.e. CSMA) • Eliminate frequent, redundant polling
‣ Improvements in protocol for lower power and higher performance. • Dense inventory management
‣ Ability to formally encapsulate subprotocols (i.e. sensor protocols) • Over-the-air standardized configuration,
‣ Peer-to-peer communications commission, and upload/download
‣ Unsolicited packet transmissions (i.e. not reader-talks-first) • Support for location services
‣ Multiple Channels
• Longer range, for sparse, typically outdoor
‣ Adjustable/Adaptive data rate networks
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3. Revised PHY
More options, but actually more uniform in design
• Designed for optimized synthesis into HW Mode 1 Mode 2
for better cost and interoperability
‣ Packet = Preamble, Sync Word, Data Channel Size 500 kHz 216 kHz
‣ Single Bit period across entire packet
Channels 1 8
‣ Uses filtered FSK (nominally GFSK)
Modulation FSK ± 50 kHz GFSK ± 50 kHz
• Designed to support different regulatory
environments, optimally. Encoding Options Manchester PN9, FEC
‣ Configuration of Output Power
Normal: 55.6 kHz
‣ Configuration of available channels (up to 8) Symbol Rate 55.6 kHz
Turbo: 200 kHz
‣ Out of channel power limitations
Min: 27.8 kbps
Data Rate 27.8 kbps
• Basic PN9 allows for better data rate than Max: 200 kbps
today’s Manchester, optional FEC allows for
greater range & signal strength. Packet Sync Pulse width Sync word
Nominal TX EIRP N/A 0 dBm
• Similar enough to existing ISO 18000-7 PHY
that devices could reasonably support both Peak stopband EIRP N/A -40 dBm
old and new modes.
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4. Device Settings
New
Beyond just “tag & reader” Gateway
• Designed to handle traditional, Old
tag-reader architecture and peer-to-peer Interrogator
networks alike.
Power Consumption
• Subcontroller and Endpoint are generally
intended for the same hardware platform
(low cost SoC).
• By switching between Endpoint and
Subcontroller regimes, a single device can New
quickly go from tag-like to reader-like Subcontroller
behavior.
• Each device setting has a standardized, Old
state-based device operation for greater Tag
interoperability & consistency. New
Endpoint
Capability
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5. Revised MAC
Still a wake-on MAC, but modernized for today’s digital RF
• Wake-on design: ideal for asynchronous Mode 1 Mode 2
communication in uncertain environments,
but better than before. Addressing Unicast, Broadcast
Unicast, Broadcast,
‣ Supports external events, like sensor alarms Multicast
‣ CSMA method allows reliable transmission of
Reader-Talks-First, CSMA,
packets and superior channel efficiency. It works Access Methods
Slotted Aloha Reserved Slots
in Reader-talks-first or non-RTF modes.
‣ Synchronizer Packet (Countdown Packet Train) is Beacon Support No Yes
a new tool that makes UHF wakeup much more
power-efficient (10x), more customizable, and Multi-hop No Yes
more interoperable than before.
Mesh routing No No
• Still mostly session-less, but with:
‣ Filtering of adjacent networks Session Network ID, Session ID,
Session Attributes
‣ Ad-hoc encoding options (crypto, FEC, etc) incrementer Session Encodings
‣ Data fragmentation is now in the protocol domain
Fixed length, non-data Variable Countdown
entirely (no Session incrementer) UHF Wake Event
wakeup tone Packet Train
• Multicast Addressing replaces cumbersome Anything attributable with
Table Commands. Other Wake Events None
a 15963-style ID
Copyright © DASH7 Alliance

6. Revised Data Elements
Emphasis on data interoperability and backwards compatibility
• UDB is now readable and writeable UDB Elements
‣ Searchable (accepts queries)
Addressing Data
‣ Writeable, to defined and undefined (i.e. user) elements Device Feature List
‣ root/admin/guest privilege model PHY Configuration
MAC Configuration
• UDB stores PHY, MAC, and Protocol device configuration Channel Scan Configurations
registers, common among all devices and interoperable. Supported Sub-Protocols List New
UDB Type List DASH7
• UDB stores and supports all legacy UDB Elements Data Block List
Location Data List
• UDB stores data elements for encapsulated features IPv6 Address & Config
‣ Sensors (ISO 21451-7 compliant) Sensor Data & Alarms
‣ Authentication & Security (ISO 29167 compliant) Authentication Keys
‣ Other future features, like IPv6 address support
Routing Code
• New RDB (raw data block), is backward compatible with old, User ID Old &
informal raw data block, but adds root/admin/guest privilege Hardware Fault Status New
model. UDB Ext. Services
DASH7
Application Extension
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