March 28, 2019

Case Study: Lowering Backbone TCO in PNG with All-Outdoor Radio

By Stuart Little, Director of International Product Line Marketing

Papua New Guinea, or PNG, is one half of the island of New Guinea, along with offshore islands, located in the South Pacific immediately to the north of the Australian continent. The country is rugged and heavily covered by dense rainforest, which presents enormous challenges when it comes to establishing a national communications infrastructure. In most cases, deploying fiber routes is simply not practical nor affordable. Wireless is the only answer in these cases.

Figure 1: Papua New Guinea Backbone Project location

One of the national mobile operators in PNG needed to upgrade and replace their existing backbone network across the north-eastern coast of the mainland. The operator has been operating a combination of aging all-indoor trunking radios, augmented by satellite links.

This operator is now rolling out a modernized network based on 4G/LTE, which dramatically increases demands on this backbone network. The satellite links are severely bandwidth limited and prohibitively expensive, which the trunking radio links were also capacity limited and expensive to operate, due to the need for air-conditioned shelters on sites often maintained by diesel generators. The objective was to significantly increase capacity and at the same time slash operational costs.

Moving High Capacity Trunking from All-Indoor to All-Outdoor

Legacy trunking radios deployed in the PNG network, required a substantial site infrastructure, including walk-in shelters that could accommodate a 2m high equipment rack, which then needed to be air-conditioned due to the sensitivity of the equipment to high temperatures experienced in the tropics. The net result was very high power consumption, which directly equated to high fuel costs where off-grid sites are maintained using diesel generators. All-indoor radios also required expensive elliptical waveguide to connect to the antenna, which in turn needs to additional equipment to remain pressurized and free of moisture and is awkward and expensive to install.

Figure 2: Typical Trunking site infrastructure, including cabin/shelter, diesel generator, and fuel storage

In contrast, Aviat’s New Trunking solution can be deployed as an all-outdoor footprint, without the need for any indoor equipment at all. This can reduce or even eliminate indoor related costs, including air conditioning, removes the need for waveguide, and reduces power consumption while also supporting much higher capacities. Lastly, locating the radios up on the tower without waveguide increases overall system gain, which can enable smaller antennas, reducing tower costs, such as strengthening and leasing-related.

Figure 3: Potential TCO Reduction using Aviat New Trunking Solution

The Solution

The Operator immediately recognized the advantages of Aviat’s proposed solution, the foundation of which is the WTM 4000 radio platform. This supported a number of features that enabled Gigabit long haul connectivity, even over distances in excess of 100km over water.

• All-outdoor, zero-footprint architecture, which needs no indoor equipment, and is fast and simple to handle and deploy;
• Dual transceiver architecture, enabling double capacity capability in a single outdoor radio enclosure;
• High modulation support, up to 4096QAM enabling 50% or more improved frequency efficiency compared to legacy trunking radios;
• Extra-wide 112 MHz channel support, enabling 4x capacity increase in a single radio, compared to 28 MHz.
• Integrated Space Diversity (SD). SD is needed to mitigate fading effects on long over-water paths. WTM 4000 supports a fully integrated SD capability in one outdoor unit, without the need for a second radio;
• Low power consumption. Aviat’s WTM 4000-based solution enabled a reduction of DC power consumption on a typical site to be reduced from 3 KW to only 500 W, equating to a significant Opex saving in terms of fuel costs;
• IP/MPLS-ready. WTM 4000 can be upgraded by software, with no additional hardware required, to support IP/MPLS when needed in the future to support more advanced service segmentation and provisioning.

Challenging Path Designs and Conditions

This network was designed and implemented to deliver high capacity, Gigabit connections over long distances, over mountainous and forested terrain, and also over expanses of water in excess of 100km.

Aviat brought their decades of link design experience to ensure that these links support up to 99.999% availability.

For this project Aviat also provided full Turnkey deployment services across challenging terrain, which often required transport of equipment to remote sites without road access, forcing the use of helicopters.

Figure 4: Transporting equipment (including antennas) to site by helicopter

The result

Aviat implemented the WTM 4000-base New Trunking network in PNG that resulted in a significant increase in capacity, while also reducing overall TCO, by taking advantage of the latest in microwave technology developments in a compact and all-outdoor design. The operator now has the foundation to deliver the next generation of LTE services to their customers cost effectively with future-proof capability.