On February 28, 2019 the first six OneWeb Low Earth Orbit (LEO) satellites were successfully launched aboard an Arianespace Soyuz rocket.  With this launch the implementation of CEO Greg Wyler’s vision to provide “broadband access for everyone, everywhere. On land, at sea, and in the air” has begun.  More significantly, his vision encompasses having a “5G ready network in space.”  A marked-up $640 million question then becomes – can the latency limitations of satellite communications (SATCOM) be overcome to meet 5G’s challenging requirements?

Now everyone has heard the clichéd real estate agent’s mantra – location, location, location – which conveys the desirability or lack thereof of a piece of property. Similarly, in the much desired “broadband everywhere” networking world—which happens to be a core objective of 5G services—it’s all about latency, latency, latency!

In February 2017, the 3GPP (3rd Generation Partnership Project) defined 5G service requirementswith performance targets for different scenarios (e.g. urban macro, rural macro, indoor hotspot) and applications (e.g. remote control, monitoring, intelligent transport systems, and tactile interaction), for example:

• User experienced data rates vary, from 1 Gbps downlink and 500 Mpbs uplink for indoor hotspot environments to 50 Mbps downlink and 25 Mbps uplink for rural macro environments.
• Latency targets, an important performance indicator for 5G, are as low as 0.5 ms for tactile interaction.
• Capacity targets can be as high as 15 Tbps/km²with 250 000 users/km²for indoor hotspots such as office environments.

The Marketing Id (MID) has italicized 5G’s latency requirements above to make a point – 0.5 milliseconds is “wicked fast,” as the gaming kids would call it.  To understand 5G’s latency requirements from a SATCOM perspective, MID referred to Doug Mohney’s April 27, 2018 article, “5G and satellite – It’s complicated.” Per Mr. Mohney, “Today’s satellite broadband services, with few exceptions, run into a latency brick wall.”  Notwithstanding 3GPP’s stringent requirement, Mr. Mohney believes that the real-world use “will likely run single digit or low double digits”milliseconds of latency.

In further gauging the practical feasibility of satellite’s role in 5G, Mr. Mohney points out:

“LEO communications constellations, the new hotness in the satellite industry, should drop latency to between 25 to 50ms, depending on which provider you talk to and how close you fly to Earth. While 25 to 50ms isn’t exactly a 5G single digit latency promise, it’s probably good enough for most real-time communications applications, including voice and gaming.”

Mr. Mohney also holds out promise for “MEO-style networks with satellites located between 1,200 miles and 5,000 miles above the earth get us into the ballpark where satellite becomes useful for voice and data services without paying a ‘latency penalty.’”

Despite this latency penalty that’s inherent in SATCOM, there are still some obvious use cases that it offers.  As Nicolas Chuberre and Cyril Michel explained so clearly in their January 4, 2018 article, “Satellite components for the 5G system,” there are features that SATCOM can best assist 5G with, as in:

1. Help foster the 5G service roll out in un-served or underserved areas to upgrade the performance of terrestrial networks.
2. Reinforce service reliability by providing service continuity for user equipment or for moving platforms (e.g. passenger vehicles-aircraft, ships, high speed trains, buses).
3. Increase service availability everywhere; especially for critical communications, future railway/maritime/aeronautical communications.
4. Enable 5G network scalability through the provision of efficient multicast/broadcast resources for data delivery towards the network edges or even directly to the user equipment.

From a marketing standpoint, the satellite operator’s partnership with a 5G mobile network operator (MNO) offers unique selling points that are clearly established in the above-mentioned use cases. So, a SATCOM marketer doesn’t really need to sell the obvious advantages of satellite technology to 5G broadband services providers.  SATCOM’s value-add when integrated into 5G networks—in un-served and underserved areas, in moving platforms, in ubiquitous availability of critical communications, and in network scalability via multicast/broadcast functionality—provides MNOs the ability to differentiate their 5G service offerings with varying levels of competitive advantage depending on what their market segment’s use case(s) demand.   Thus, the 5G-ready LEO services should be ready to roar out the gate and hopefully enhanced MEO services will overcome the latency penalty in supplementing 5G data and voice services.