Multi-Carrier Link Aggregation


A Spectrum Perspective

Microwave radio spectrum is fragmented and uneven across the traditional frequencybands. Furthermore propagation behaviour is different as we grow in frequency. The resulting picture is that some frequency bands are more heavily used then other, either because those frequency bands are open and made available worldwide, or simply because better fit the need of mobile backhauling representing the biggest application of the market. Consequently we will also have other frequency bands underused, regardless of spectrum width availability.
In the below qualitative picture we represented how frequency impact distances, as well as the usage of the spectrum, showing the portion between 15GHz to 23GHz being congested, and the available bandwidth per frequency band.

graph

The highest congested frequency band groups are characterized by a low spectrum availability, while high frequency bands offering also a wide spectrum are generally underused.
Multi-Carrier Link Aggregation offers a solution to smartly couple different frequency band and respective bandwidth as if a single logical pipe, offering the advantage of long reach of one frequency band, with higher capacity of the other, with a smart management of traffic priority vs link availability.

dual band single antenna

 

Hybrid Link

With the term of Hybrid link we identify the bonding between a standard frequency band (e.g. 18GHz) with the millimetre frequency band of 80GHz.
With hybrid link we combines Ultra high capacity of E-Band Radio with the Higher Availability of a standard licensed frequency band.

Applications

  • Extends E-band hop length to several kilometers, exceeding urban reach
  • Upgrade capacity of existing Microwave hops without impacting availability and limiting OPEX costs impact

When experiencing high traffic growth in the network adding to an existing deployed link an 80GHz link in link aggregation offers a drastic capacity growth (4 times extra capacity) with limited OPEX costs, taking advantage of the little to no license schemes regulating millimetre wave frequency bands.


Furthermore with the smart coupling between a licenced band and an 80GHz band, the link could be extended from the traditional urban distances to reach sub-urban/rural lengths of 10Km.

hybrid link siae                                                                                (Expansion of an existing link scenario)

This solution can be achieved coupling several ODU types, either via IF cable or Ethernet. The bonding can be achieved between an ALFOplus80HD (80GHz) with an AGS20 in any configuration from simple 1+0 (resulting in a 2+0 link as represented in the picture above) to more complex configurations e.g. 2+0 xpic (resulting in a 3+0 link). This allows operators the freedom to address a wider option of cases, as well as upgrade existing link in any configuration, maximising the benefit throughout the network.

Multi Band Link

The same behaviour can also be achieved by aggregating two links from two licenced frequency bands.
With Multiband link we exploit available spectrum at higher licensed frequency bands while leveraging on extra reach of lower licensed frequency bands

Applications

  • Relief Bandwith of congested spectrum of lower frequency bands
  • Upgrade capacity of existing Microwave hops without impacting availability

Conclusions

The use of Multi-Carrier Link Aggregation is another tool at the service of operators to address the constant traffic capacity growth. With this implementation microwave radio plays on its strength of flexibility to re-arrange existing components to provide a new way to offer connectivity.

SIAE MICROELETTRONICA solution:

-Based on already available products
-No dedicated hardware needed
-Fully hitless solution in any stage of RF state change
-Lowest power consumption solution
-HQoS of smart traffic management

SIAE MICROELETTRONICA related microwave radio equipment: