Metro Network
Also known as: Metropolitan Area Network, MAN
Definition
The transport infrastructure layer connecting access sites, aggregation points, and data centers within a single metropolitan area or region, built on optical transport and carrier service technologies, sitting between local access networks and long-haul wide-area connectivity.
Key Points
- Spans a metropolitan or regional geographic scope, sitting between local access networks at the edge and the long-haul wide-area network connecting cities and regions, rather than covering either extreme
- Typically built on DWDM optical transport to maximize capacity across metro fiber routes, with Carrier Ethernet commonly used as the service layer delivering connectivity between specific sites within that metro footprint
- Aggregates traffic from numerous access sites — cell towers, business locations, data centers — before that traffic continues onward into the wide-area network or a data center, functioning as a regional concentration and distribution layer
- Provides the fronthaul and midhaul transport connectivity that distributed radio access network architectures depend on, connecting radio units, distributed units, and centralized units across a metropolitan footprint
- Metro network capacity and topology decisions directly shape what density of access sites — cell towers, small cells, enterprise connections — a given metropolitan area can practically support, making metro infrastructure a first-order constraint on regional network densification
Concept
A metro network gathers traffic from numerous individual access points across a metropolitan footprint — cell sites, business locations, smaller aggregation nodes — and carries it across the metro area to larger aggregation points, data centers, or the gateway into the wide-area network, using DWDM's capacity multiplication and Carrier Ethernet's standardized service delivery to handle the aggregate traffic volume a dense metropolitan area generates.
Explainer
The metro network's position between access and wide-area connectivity makes it a frequent bottleneck consideration in network densification planning, since adding capacity or density at the access layer — more cell sites, more small cells, more enterprise connections — only delivers value if the metro network aggregating that traffic has the capacity to actually carry it onward, meaning metro infrastructure investment and access-layer densification need to be planned together rather than independently. This is precisely why modern distributed radio access network architectures, which split radio processing across multiple physical locations connected by fronthaul and midhaul links, depend so heavily on metro network capacity and topology — the connectivity between those distributed processing points is itself metro network traffic, adding directly to whatever other aggregation demand the metro layer already carries. For CE verticals, metro network capacity is a background but consequential factor in urban and regional deployment planning — a telecommunications operator or large enterprise planning dense connectivity across a metropolitan area needs metro network capacity assessment as an early planning input, not an assumption resolved automatically once access-layer plans are finalized.
Cite this entry
Metro Network. ConnectedEarth Knowledge Base. https://connectedearth.space/knowledge-base/metro-network/ (updated 13 September 2026).