MCF 2022 – Australian Standard for Distributed Antenna Systems (DAS)

The much-anticipated MCF 2022 was released in August 2022, providing clarity to the industry on the requirements for Distributed Antenna Systems (DAS) for the years to come. For the most part, there are not too many surprises, with the overall focus being on 5G coverage metrics, additional 3.5GHz band support and further capacity via MIMO. This article will detail some of the key differences which have been included in MCF2022 when compared with the former MCF2018. The article doesn’t cover everything you need to consider in DAS design, just the key differences between the iterations of the MCF specification.

The Mobile Carrier Forum (MCF) is the governing body for DAS specifications in Australia and is made up of a collective between Telstra, Optus and TPG (trading as Vodafone). The MCF2022 specifications and other relevant information are published on the AMTA website.

IMPORTANT UPDATE: In December 2022 the MCF2022 was withdrawn from the market with the industry reverting back to MCF2018 while awaiting further updates. MCF2023 is a revamped document issue to the industry for consultation

The Transition to MCF2022

The MCF2022 allows for a period of transition to migrate to the new specification, during which time DAS can still be deployed to legacy standard to facilitate the completion of projects ‘in flight’. Designs that are lead carrier approved and have a lead carrier contractually signed on for connection prior to 30 June 2023 will be accepted under the existing MCF2018 specifications. Realistically operator connection proposals and execution can take some time, so to be safe, Wireless Coverage Solutions would be aiming to have designs completed by ~March 2023 to ensure sufficient time. (We expect to see a bit of a last-minute surge!)

During the transitional period, MCF2022 encourages sites to consider upgrading to MIMO or, at a minimum, the extended bands to allow for 3.5GHz. Realistically, most DAS scoping documents already consider the extended bands and have been facilitating upgrade pathways for some time.

Note. The transitional process differs for high-end infrastructure projects, which are more likely to need to adopt MCF2022 sooner rather than later, given the time between design and execution. This is typical on larger projects which will require consultation with a lead operator

DAS Topologies in MCF2022

The MCF2022 refines the use of industry terminology in describing various kinds of DAS topology and, in doing so, realigning with the international vocabulary. This removes any ambiguity and confusion, particularly around the terms Active and Hybrid solutions, which are commonplace in the industry.

Passive DAS: A system with no active elements, a coaxial RF source plugs directly into a coaxial-based system

Hybrid DAS: A mixture of Active and Passive. Typically, this is done in the form of a ‘High Power Active DAS’ whereby high-power remote units feed segments of coaxial cable. It could also refer to a site with a combination of Passive and Active segments (for example, passive in a car park, and Active in more capacity-demanding areas)

Active DAS: A system in which RF signal is conditioned and then connected to an Active DAS headend which converts the RF to structured cabling (often fibre), which is distributed to Low Power Active DAS Remotes (similar to a Wi-Fi Access Point). Once the coaxial is connected to the headend, it is never converted back to coaxial again.

Digital DAS: Essentially an Active DAS, but the connection to the DAS is done through fibre rather than the RF ever needing to be generated.

We have an entire article dedicated to understanding the various kinds of DAS topology in more detail here:

DAS Equipment Rooms

We have an entire article dedicated to DAS Room considerations here, recently updated to reflect MCF2022 changes. This goes further into the details of how a DAS room can significantly impact the cost of site deployment through strategic placement in the building.

Operating Frequency Bands in MCF2022

MCF2018 DAS band support has been required from the 700MHz band to the 2600MHz band. Informally the industry has been providing a large amount of support to the 3.5GHz bands already. This has largely been managed by the removal of legacy components from approved equipment lists that don’t provide for 3.5GHz compliance.

A new MCF2022 challenge is a requirement for the newly reshuffled 850E band, with the ‘E’ meaning ‘extended”. This band is not currently supported by any operator-approved Active DAS hardware (High or Low power variants), which leaves some catching up to do on the front of the approval. A Passive system will be able to pass the 850E band without issue, but active remains an immediate challenge.

As expected, the MCF2022 calls out mmWave solutions (26GHz) as a completely different capacity solution which is to be deployed independently of the DAS specifications outlined in MCF 2022 and on an as-needs basis, likely operator by operator.

MCF2022 makes 3.5GHz compliance mandatory on all systems. 3.5GHz is a somewhat casual terminology for what is actually a very large piece of the spectrum from 3400-3800MHz, so don’t be surprised if you hear people talking about 3.6GHz, 3400MHz or 3800MHz, it’s all the same band.

A specific coverage target of > -100 dBm RSRP has been applied for 5G at the 3.5GHz band to compensate for the inherent attenuation that comes with higher frequency signals. For a further understanding of how frequency bands impact coverage and building penetration our intro to DAS could be helpful, located here

Multiple Input Multiple Output (MIMO)

Up until now, Single Input Single Output (SISO) systems have been the default DAS deployment, with a 2×2 MIMO configuration being optional in MCF2018. Outside of major infrastructure (tunnels, airports, stadiums) often MIMO has not been widely taken up, largely due to the significant increase in DAS deployment costs associated with it.

MCF2022 calls for the deployment of 2×2 MIMO in all areas other than car parks. The performance benefit of MIMO is essentially a theoretically doubling in the maximum data rates. This doubling allows for increased maximum speed (and bragging rights) and overall holistic capacity across the site spread across many users. However, achieving this increase also means a doubling in cabling, components and installation effort, as such, the cost increase associated with MIMO is significant.

If you would like to understand more about what MIMO systems are, we have an article on the specific topic here

Lift Coverage in MCF2022

Largely unchanged with coverage being provided from the lift lobbies still being the predominant solution.

The MCF2022 does allude to ‘in lift car’ solutions to be discussed with the lead operator. Currently there is no approved hardware to facilitate this implementation, however, it’s a welcome addition when the approvals process catches up. This is typically only viable on new developments and will require the lift car companies to participate and provide fibre connectivity and power atop lift cars. The number of fibres could prove problematic based on the required 7-band solution for Lifts.

Coverage Areas in MCF2022

Much like the previous specification, MCF2022 is very specific in its requirements for different areas within buildings as well as types of buildings. An area’s use and capacity requirements differ, and so do its solution requirements.

These areas are then assigned a capacity type which has implications for the number of bands required and the whether the solution should be SISO or 2×2 MIMO.

There is requirement for lift lobbies to be an Advanced area is particularly unusual as it increases the band requirements in areas that would have otherwise been 3 bands up to 7 bands (and significant cost implications).

For example, office buildings that would have been Standard 3 bands, now require Advanced 7 bands in lift lobbies. Presumably, this is to facilitate low band coverage into lifts but ultimately makes the ‘Standard’ class somewhat irrelevant. This change impacting a small portion of the floor (the lift lobby) typically will require the whole floor to support the Advanced configuration as a result.

Summary

In summary, the new MCF2022 provides further clarity on the transition to 5G for new DAS deployments, albeit with a significant cost uplift for landlords. It should be noted that many existing deployments are capable of supporting the deployment of 5G on bands other than 3500MHz. This will typically be at the mobile operator’s discretion and is taking place today.

To better understand how the recently released MCF2022 could impact your in-building mobile coverage project, don’t hesitate to get in contact with us at Wireless Coverage Solutions.