User's Manual

Bridges Hardware Guide Silver Spring Networks 31
Glossary
link quality The overall RF quality of a link between
a transmitter and receiver. Often expressed in terms
of message success rate and signal strength. See
MSR and RSSI.
link budget The total amount of RF power available
to establish a link between the transmitter and re-
ceiver, expressed mathematically:
PLinkBudget = PTx - PTxLoss +
PTxAntenna + PRxAntenna -PRxLoss -
PRxSensitivity
LOS Line of Sight. A direct path, free of clutter, be-
tween a transmitter and a receiver.
M
MAC Media Access Controller. A unique hardware
identifier for network equipment.
MLME Media access control (MAC) Sublayer Man-
agement Entity. An internal process handler for es-
tablishing L2 network adjacencies and routing in the
Silver Spring RF wireless mesh network.
MSR Message Success Rate. The percentage of
packets that are transmitted (by the Access Point)
and also acknowledged (by the meter). The MSR is
derived from successful packet transmission during
scheduled reads, On Demand reads, and segment
retries. MSR is a metric for packet transmission and
how well the Access Point can communicate with a
meter. See also BSR and RSR.
N
neighbor table A memory structure within each NIC
to store data about its neighboring NIC-enabled de-
vices.
net metering Net metering applies to energy custom-
ers, such as commercial and industrial users, who
both generate and purchase power. Utilities need to
meter the power generated by customers to deter-
mine the credit the customer should receive. A net
register calculates energy to be billed by subtract-
ing power received from the customer from the
power delivered to the customer.
network discovery When a new meter is first in-
stalled, it broadcasts a discovery message. The dis-
covery message is received by all NIC-enabled
devices in range, which in turn, forward the mes-
sage upstream through an Access Point to AMM.
node A network device. Examples include electricity
meters, Relays, and IMUs.
NIC Network Interface Card. Attached to electricity
meters and integrated with Water and Gas IMUs,
the NIC card provides two way radio communica-
tions across the network.
O
ODS Outage Detection System. An application from
Silver Spring that manages outage-related messag-
es from electricity meters, including last gasp and
power restore messages. Unlike an OMS, and ODS
does not include a work order management system.
OMS (OM) Outage Management System. A central-
ized system that manages the identification of all
outage events and the restoration of service in a
utility grid. An OMS system usually is tightly inte-
grated with a work order management system.
one-time schedule A schedule with a frequency of
one-time. See also schedule.
OSI Open Systems Interconnection. A standard refer-
ence model for how messages are transferred be-
tween any two points in a network. The OSI
reference model defines seven layers of function
that take place at each end of a communication. It
serves as a standard by which diverse applications
can communicate with one another.
over-the-air Wireless communications between de-
vices. Sometimes used to refer to the programming
of devices through wireless communications.
P
packets Packets consist of a header, which contains
data such as destination address, and a payload,
which contains application data such as interval
read results. See payload and ping.
packets in flight The number of simultaneous pack-
ets being transferred between a sender and a re-
ceiver. A packet in flight is one that the sender has
sent but the receiver has not yet acknowledged as
received.
parent A network device to which other devices are
registered.