How 5G Could Kill Distributed Antenna Systems (DAS)

Ed Gubbins – Senior Analyst

Summary Bullets:
• DAS will face steep hurdles in evolving to the 5G era.

• Vendors of distributed small-cell enterprise RAN solutions, once content to aim down-market from DAS, are increasingly aimed at competing with DAS head-on, exploiting DAS’s 5G vulnerabilities.

• However, any threat posed to DAS by 5G is likely to take years to have effect, increasing the long-term uncertainty surrounding these trends.

5G — in its early implementations, at least, aimed at mobile broadband, rather than the Internet of Things (IoT) — will be more evolution than revolution, boosting speeds that were already increasing steadily via advances in LTE technology. But in at least one respect, even 5G mobile broadband promises to do something truly disruptive: It could mean the demise of DAS.

That’s no small matter. Some estimates put the global DAS market well north of $6 billion annually. Walk into any stadium, hospital, shopping mall, or big-box store and make a mobile call; odds are you’re using a DAS, a carrier-neutral network that distributes the signals of multiple operators using shared antennas and other gear so that each operator doesn’t need its own separate in-building network.

In 2013, when major RAN vendors unveiled new enterprise small-cell solutions with distributed architectures reminiscent of DAS, they primarily targeted a market segment that was mostly tangential to DAS. Ericsson’s Radio Dot System and Huawei’s LampSite aimed at an unserved “middle” market in the enterprise space. Small enterprise venues that needed better indoor cellular coverage could be served by standalone small cells (picocells with baseband, radio, and antenna all in one box). Large enterprises were already being served very commonly by DAS. But it wasn’t cost-effective to deploy either picocells or DAS in medium-sized enterprises. That said, the high end of the enterprise market was widely regarded to remain the safe province of DAS.

Today, however, Ericsson and Huawei are no longer content with just that neglected middle-ground. Now they’re eyeing the entire DAS market, including the largest enterprise venues, and contemplating a day when DAS is a thing of the past. Although this shift has been happening for some time now (e.g., Huawei was pushing more direct competition with DAS in 2014), 5G is fueling a more aggressive level of competition.

“We are going to replace DAS totally,” a Huawei executive told me recently. “5G is the end of DAS.”

The rationale behind this vaunted ambition is that DAS will have difficulty evolving to 5G, for multiple reasons, including:

High Frequencies. “Optimal” 5G will employ a mix of low, medium, and high frequency bands, but those high frequency bands (e.g., millimeter wave) will be difficult for DAS – passive DAS in particular (which uses components without active electronics).

MIMO. Even active DAS (with active electronic components) will face hurdles because migrating to 5G will require higher antenna arrays – e.g., 4T4R – which could be difficult or prohibitively expensive for DAS. And without higher orders of MIMO, beamforming – a fixture of 5G discussions – isn’t possible.

Value-Adds. Over time, the ability to layer services on top of 5G networks, from IoT to analytics-driven services, is something traditional DAS is not designed to do.

Some DAS providers have been hedging their bets regarding the threat from small cells for some time now – moves that position them well for the mounting threat to DAS posed by 5G, even if they weren’t necessarily prompted by that threat specifically. For example:

• CommScope, a major DAS provider, acquired enterprise small-cell vendor Airvana in 2015.

• Corning, which has a significant DAS business in addition to its fiber and other assets, acquired enterprise small-cell vendor SpiderCloud last year.

Meanwhile, small-cell vendors have made changes to their portfolios that support more aggressive competition with DAS:

• Huawei introduced a new version of its LampSite enterprise RAN solution, LampSite Sharing, which can accept CPRI or RF inputs, allowing it to interoperate with other vendors’ gear and function more like DAS.

• Ericsson introduced a multi-operator version of its Radio Dot System in August 2017 and a 5G Dot in January 2018.

All that being said, whatever the challenges 5G poses for DAS, it will take years to make a dent. 3G and 4G needs are going to linger for some time (particularly given 5G’s initial reliance on 4G), forestalling DAS’s demise. And remember: thus far, it’s been a hard slog for small-cell solutions trying to penetrate enterprise environments (thanks to, for example, business-model hurdles and WiFi’s incumbent dominance), most of which have not offered multi-operator support until recently – if at all. And multi-operator support will, of course, be key in displacing DAS. Likewise, it will take some time for demand for 5G in enterprise environs to simmer. And the longer it takes for these trends to play out, the less predictable they can be.


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