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UTILITY COMMUNICATION NETWORK In contrast, meters generally do not connect directly to
ARCHITECTURE the FAN. Instead, they connect to the Tier 3 Advanced
Most utilities implement a two- to four-tier smart grid Metering Infrastructure (AMI) network (see below) and
communication network architecture, depending on the the AMI collectors that aggregate data from meters in a
specific applications they plan to deploy. The tiers are neighborhood provide the connection to the FAN. FANs
defined as follows and illustrated in Figure 2, below: are most often implemented with wireless networking
• Tier 1: The utility’s core IP network. This tier is technologies, usually mesh or a combination of mesh
generally implemented with fiber-optics. Where fiber is and PTMP, because their large geographic coverage
not available and is infeasible to implement, point-to- areas, large number of connected devices and the need
point (PTP) and point-to-multipoint (PTMP) wireless links to support mobile field workers make it technically and
are usually employed. In most cases, the Tier 1 network economically infeasible to implement them using wired
provides a 10/100BASE-T Ethernet port on a virtual local technologies.
area network (VLAN)-capable Ethernet switch as the • Tier 3: The AMI networks, also known as
demarcation point for the Tier 2 FAN. Neighborhood Area Networks (NAN), include meters
• Tier 2: The Field Area Network (FAN) fills the gap and AMI collectors. Meters may communicate directly
between the core Tier 1 networks and devices, as well as with collectors or via other meters using a meter
personnel, in the field. Devices such as capacitor bank meshing system. The AMI network will also provide the
controllers, recloser controllers, load tap changers, etc., communications interface for the Home Area Networks.
used to implement distribution automation functions such • Tier 4: The Home Area Networks (HAN), usually
as active Volt/VAR management usually connect directly implemented using ZigBee or HomePlug technology,
to the FAN, as do apparatus for implementing substation provide connectivity to smart grid devices inside homes
automation, distribution generation, renewables integration, and businesses. If supported by the meters used in the
energy storage, etc. The FAN also provides connectivity AMI system, HANs can connect to NANs, and, in turn,
for laptops, tablets and handhelds used by field workers. the rest of the utility communication network, via the smart
meters deployed on the customers’ premises.

Figure 2 – Typical Smart Grid Communication Network Architecture

A different view of the typical utility communication network architecture, showing how the tiers relate to components of
the electricity distribution system, is show in Figure 3.

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