In part one of this series, we talked about the three
types of networks: multi-service organization, telephony networks and a
traditional cellular network. They all look different when deployed due to the
need to meet different communications applications. And when it comes to
converging them, there are three things needed.
We’ve already discussed
the power requirement, and its importance to a converged network. Now we’ll
talk about the final two.
Backhaul (data from the edge
access points to the central data storage or processing centers)
Traditionally backhaul
from cell sites has been done either though high-speed twisted pair, microwave
or fiber links from radio locations to centralized equipment locations. These can be dedicated links or shared via
time domain or wavelength-division multiplexing.
In an existing HFC
network, backhaul capacity can also be provided via DOCSIS. DOCSIS provides
connectivity over either coaxial or fiber links. Equipment to condition power
from the HFC plant to activate wireless access points via PoE (power over
Ethernet) while providing a DOCSIS channel also exist. For small cells, depending on the technology
deployed, tight timing and latency requirements are a concern, but these issues
are currently being addressed in standards organizations.
“Fronthauling”
wireless data employs CPRI (Common Protocol Radio Interface) signaling. This signaling technology is currently
required by LTE radios if coordinated multipoint is deployed to allow for the
reuse of spectrum and mitigates interference. The dedicated link is usually a
pair of fibers per radio deployed, but a fiber pair can be shared for multiple
fronthauls via WDM, as long as the signaling paths are independent and no
longer than 15 km.
New technologies such
as the packet switchable ECPI standard are also evolving. The intent of this new standard is to
decrease sensitivity to new required 5G latencies, reduce required data rates,
and still allow for centralized radio coordination to reuse spectrum.
Site acquisition
Going forward, most
wireless mobility to be deployed for LTE densification or 5G will be deployed
in high capacity urban and suburban areas.
CLICK TO TWEET: What are the three necessities for successful network convergence? CommScope's John Chamberlain outlines them.
Site acquisition is
always a major part of any wireless network.
Typically, it takes time and money to secure. The 4G/LTE wireless
densification effort is about capacity, not coverage, and 20-30 feet in the air
is adequate for the coverage of a small cell area to create the additional
capacity desired. For underground plant,
small cabinet based cells are available, with varying tower heights and a
variety of concealment methods. These
small calls can be very unobtrusive, and placed along right of way already
established for pedestals and cabinets.
Convergence of our
telecommunications’ networks is a natural economic and technical evolution
expedited by wireless small cell densification.
Power, backhaul and site availability are of utmost importance in the
design of any radio access network.
Throughout 2018 and beyond the migration toward network
convergence will continue. The physical assets
of networks will begin to be consolidated, and the same plant facilities will
be used for wireless backhaul/fronthaul, FTTx, HFC, fixed wireless access, and commercial
high speed data requirements via a highly leveraged optical fiber facility. NFV
will continue to evolve as well, making all central processing facilities,
whether datacenter, headend, central office, or mobile switching center all
resemble each other running applications on COTS and eventually physically
merge.
In addition, the signaling technology in the outside
plant will migrate toward an IP, packet-switched network allowing for the convergence
of different service’s signals within the same data stream.
Vendors understand and are aligned to facilitate
the financial motivations for network convergence and the need for cost
effective solutions. New solutions are
being developed to facilitate convergence, and more will be coming in the next
few years.