In the prior installment of this series, we discussed the potential cost and logistics of requiring resources (rack space, power, HVAC) from the enterprise as part of improving cellular signal indoors. FYI, if you are new to this series and want to get the most out of it, please start here, and read the posts in sequence.
This post covers the infrastructure that interconnects the Telecommunications Rooms to the building’s Equipment Room. First, let’s set some context on how Telecommunications Rooms relate to the overall building. Every floor has at least one Telecommunications Room that supports all the needs of that floor. Each of the Telecommunications Rooms are directly connected to the Equipment Room.
Telecommunications Room Design Elements:
- A Telecommunications Room supports a wiring zone where every location that a physical network cable is installed is no more than 100 meters from the room.
- Located in the core of building.
- Stacked on top of each other. This is so cabling can be easily run vertically through the building from the lowest floor to the top.
- The fiberoptic cabling that is terminated in a floor’s Telecommunications Room is an unbroken run from the Equipment Room.
The fiberoptic cabling between the floors is a major construction project to get into place. It’s elements are:
- Permits and civil engineering. The cost and complexity varies by municipality.
- Core drilling concrete floors for the cable runs. This is a messy, wet, and very loud activity that is so disruptive to business operations that it must be done on weekends or at night. Plan to pay overtime wage rates.
- Running protective conduits for the cabling with periodic pull boxes. Pull boxes are needed due to handling guidelines for fiberoptic cable and the natural friction encountered inside the conduit. To keep it simple, if you mishandle the cable as it’s pulled in, the fibers will break internally.
- All conduits need to be fire-blocked, as per local regulations, between floors so smoke or flame have no migration path between floors.
- Fiberoptic cable must be correctly strain relieved and protected from damage in the Telecommunications Room. Protection within the room is generally afforded by innerduct, which is a non-metallic flexible tubing.
- Each fiberoptic strand of the bundle contained inside the cable is terminated in a jack that is part of an optical patch panel.
- Patch cords interconnect from the optical patch lack to the active electronic equipment.
For reference: Telecommunications Room, cable pathways and other structural design elements are well documented in the EIA/TIA-569B specification.
As you can see from the requirements above, it is a significant cost where the lack of fiberoptic capacity or the wrong type of fiber is available in the targeted building. To be very clear, the need for fiberoptic cabling project applies to an Ethernet LAN for E-RAN usage or any of the alternate cellular architectures that require dedicated fiberoptic cabling to network their systems together.
Now, let’s connect all of this to indoor small cell architecture.
When E-RAN is deployed using a VLAN carved out of the existing enterprise network, impacts are:
- No need for fiberoptic capacity. The enterprise PoE+ switches are already networked together.
- No construction required between the Equipment Room and the floor’s Telecommunications Rooms.
For alternate indoor architectures that have originated by downsizing outdoor macro-cellular technology, they have separate technology end-to-end from the enterprise that has these impacts:
- Fiberoptic Consumption
- 2-4 fibers per floor needed.
- If customer cannot provide cable plant for cellular use, a construction project cost and schedule delay required to build fiberoptic capacity.
From a financial perspective, we have modeled the costs of building a LAN vs. the enterprise carving out a VLAN to host the E-RAN through a building. For a SpiderCloud E-RAN installation, the construction of a standalone LAN, with it’s fiberoptic capacity, adds an additional 24% to the project.
In following the theme of re-opening the discussion on how indoor cellular should be built, infrastructure that is common to all wireless is key to future enterprise use of small cells. We ask why build a LAN (including all it’s lifetime Capex and Opex) when your enterprise customer has already built the network? Even when the situation is Site Acquisition of a full building, the landlord may already have an Ethernet in place acting as the “digital nervous system” for building operations. This network can also host the small cell network.
To recap, E-RAN is “enterprise IT friendly” by using:
- ZERO use of fiberoptic cabling between the Telecommunications Rooms and the Equipment Room.
- Savings of 24% on the project by partnering with the enterprise on VLAN sharing on their infrastructure.
In the next installment, we will delve into facilities needs in the Equipment Room.
– Art King, SpiderCloud Wireless, Director of Enterprise Services & Technologies
Other posts from the Enterprise Deployment Series:
- Enterprise Deployment – Setting the Stage
- Enterprise Deployment – Ethernet and the Physical Layer
- Enterprise Deployment – Telecommunications Room
- Enterprise Deployment – Telecommunications Room Interconnection
- Enterprise Deployment – Equipment Room
- Enterprise Deployment – Backhaul
- Enterprise Deployment – Summary