User's Manual

UtiliNet® Endpoint User Guide 1-5-2007
Page 29 of 30
© Cellnet 2005
radio qualifies as in the same domain of the packet destination if it has the same color and its geographic
location lies within the domain qualifying radius of the final destination. During a domain cul-de-sac, a
core radio that sees a domain of the same color qualifies as seeing the correct domain if it is within this
distance of the final destination.
Domain Radio In a network using domain routing, radios are divided into “core” and “domain” radios.
Domain radios are radios that have connectivity among radios in their domain, but are not good routing
choices for packets destined to other domains.
Domain Routing Domain routing is an optional routing configuration for radios with 412 or later
firmware. It serves to eliminate undesirable routing choices by forcing packets to travel through a core
highway of radios and not route through areas of poor connectivity. The network is divided into “core” and
“domain” radios.
Domains Seen In domain routing, core radios report information to other core radios of which of the 23
domain colors they have direct connectivity to and how well it can see each one (unlike latency to core, it is
not an accumulated value). This information is used by core radios to route packets in a cul-de-sac situation
with a packet addressed to a domain. A higher value for domains seen is better. Values range from 0 to 3. A
0 represent no connectivity and a 3 represents good connectivity.
Device Address The combined 10-byte WAN and LAN address of a device.
Forward Closer to the final destination of a packet.
LAN Address The 4-byte address that uniquely identifies a particular device at a radio location. A radio’s
LAN address is its serial number.
Latency to Core In domain routing, domain radios pass information among other radios of the same
domain to indicate how well they serve as paths to the core network. Latency to core is a value reporting
how well a radio has connectivity to a core radio (either directly or through other domain radios reporting
their latencies to core – in which case the latency is an accumulated value). The better the connectivity, the
lower the latency. Valuesrange from 0 to 255. This provides information for a domain radio to route
through radios with lower latency when routing to core. This is necessary because the core radios may not
be in the forward direction (the direction of the packet destination). Latency to core is used in route to core
mode when geographic routing is not used.
Longitudinal Redundancy Check (LRC)
An LRC is a simple security check applied to each byte of a message string. A typical example is
EXCLUSIVE- ORing each byte of a message. The EXCLUSIVE-OR is a common security check but not
very robust in terms of detecting bit errors in a multibyte message. Most LRC checks are used in
conjunction with parity (even or odd).
Luck A packet parameter that controls the maximum number of “hops” that a packet can travel. Each time
the packet is passed off to another radio, the luck parameter in the packet is decremented. If the luck
reaches 0 before reaching the destination, then the packet is discarded. This limits packet movement so that
packets do not hop around forever. A luck of 255 will not be decremented and will disable this limitation
for
such a packet.
MAS MAS (multiple address system) is an acronym applied to 928 - 954 MHz radio systems. Specifically,
the MAS radios operate on 1 of 40 pairs of 12.5 kHz narrowband channels between 928 and 954 MHz –
one transmit frequency and a corresponding receive frequency separated by 10 to 12 MHz. The MAS
systems perate with a single master transmitter that transmits continuously and a minimum of 4 slave radios
at RTU sites to “hear” the master message and respond if the delivered message belongs or is addressed to
the RTU. These systems have fast response times and are generally considered to be direct replacements for
dedicated telephone circuits.
Master Station The master station is the intelligence, that is typically centrally located, which orchestrates
the system. The Master Station is also the point of MMI (Man/Machine Interface). Other names for master
station might include MTU, SCADA host, etc.
Mood A packet parameter that controls the routing of packets. It specifies how a radio with the packet
decides which radio to pass the packet on to. Each of four moods can be individually specified, resulting in
sixteen combinations. The four mood settings are “persistent,” “quick,” “reliable,” and “scram.” When all
settings are off, the mood is called “courteous.” Mood is generally represented as a 4-bit field or nibble
quantity with the bits representing the mood settings as follows:
Bit 3: L3_MOOD_PERSISTENT
Bit 2: L3_MOOD_QUICK