June 26, 2015

3 Ways to Get Smart About Nodal Microwave

At a time in the not-so-distant past, there was only one way to implement microwave radio: one radio link per microwave terminal. Did not matter what type of link it concerned: protected, non-protected or multi-channel. From the advent of digital microwave radio in the 1980s and 1990s, terminals typically had no options for integration of co-located telecom devices. And to interconnect muxes or switches required external cabling and possibly a patch-panel.

Then in the early 2000s, so-called “nodal” radios came into vogue. Designed to address the drawbacks of the one-radio-one-link paradigm, a single microwave radio node could serve as a platform for multiple links. There were still limitations when it came to radio and switch interactions, but multiple sources of traffic could now be integrated and connected on the nodal platform.

Choose Aviat Smart Microwave NodesFor approximately the last 10 years, nodal microwave radios have been Carrier Ethernet (CE) capable with full integration between radio and Ethernet switch. In addition, Layer 3 IP/MPLS capability has become more prevalent, which, together with CE, enables nodal microwave platforms to assume switching functionality.

Terminal redux
Since 2011, a movement’s been afoot and gaining momentum to bring back the one-link-per-radio terminal model. That’s not the overt objective of industry participants but the collateral effect of unintended consequences. The real goal of various microwave practitioners has been to bring forth a new low-cost concept of all-outdoor radios (ODRs). Designed as all-Ethernet/IP radios, these newest ODRs were supposed to be an easy-to-install, price-conscious alternative to traditional split-mount radio setups. These high-capacity outdoor units should have supplanted split-mounts and swept away all memory of more than 20 years of microwave market dominance.

However, the mobile backhaul market still has an abundance of TDM-only dependent 2G and 3G base stations in the installed base. And all-IP ODRs cannot support circuit-based traffic without separate adapters that must be mounted indoors. Other issues regarding power management, reliability, maintenance, aggregation and complex configurations also dog ODRs.

Layer 3 IP/MPLS enters the backhaul
As mobile phone networks have gone up the speed and capacity curves, with LTE and LTE Advanced pushing the 4G envelope, the old ways of wireless architecture don’t completely suffice anymore. With this demand for more speed and capacity from the mobile network, the mobile backhaul needs to supply a more robust solution to support 4G wireless. For business purposes, Layer 3 IP/MPLS proves to be the best answer for aggregation and edge sites.

By having IP/MPLS at the cell site, the delivery of new services accelerates. But introducing discrete IP routers into the cell site has its own considerations to take into account.

Of course, the easiest and most convenient approach to implementing IP/MPLS at the cell site is to just deploy a standalone cell site router (CSR) alongside the existing split-mount microwave radio. Though intuitively appealing, this approach has several drawbacks such as:

  • Added cost/space requirements
  • Demarcation issues
  • Management complexity
  • Lack of design with microwave in mind

Even in the new ODR model, implementing IP/MPLS at the cell site faces challenges. While designed specifically to be “plugged” into an IP router, ODR Ethernet radios have the same limitations of traditional split-mount radios in these networking configurations. In addition, ODRs must contend with:

  • Microwave configuration complexity
  • Poor performance (i.e., no media awareness)
  • Lower reliability
  • Complex power management

Smart microwave nodes
So with the traditional split-mount radio and new-fangled all-outdoor radio implementation scenarios for instituting IP/MPLS functionality both being less than ideal, what is the smart thing to do? Aviat Networks has come up with a concept called “smart microwave nodes” wherein the uniquely integrated family of CTR 8000 microwave routers is capable of pairing with split-mount, all-outdoor, all-indoor, microwave, millimeter wave, IF or Ethernet radios within a single IP address.

Managed by the ProVision network management system, an Aviat smart microwave node can function as one element in the network while supplying optimal performance for microwave and IP. To find out more, download the “Why Choose Smart Microwave?” white paper—no signup necessary.

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