Skip to main content

Skylo’s Work on Making NB-NTN Voice a Reality

At the Global 5G Evolution Workshop a couple of months ago, Soham Desai, Staff Wireless Systems Engineer at Skylo, delivered an insightful session on the progress of voice over NB-NTN and why this capability is now becoming practical. His talk walked through the state of the technology, the recent advances that make narrowband satellite voice possible, and the work being done in 3GPP to support it.

Soham began by introducing Skylo and its role in enabling direct-to-device (D2D) satellite connectivity. Skylo works with a wide ecosystem that spans chipset vendors, device manufacturers, carriers and test equipment providers. The company promotes a hybrid approach that allows a single device and SIM to move seamlessly between terrestrial networks and Skylo’s satellite network whenever coverage is needed. A large number of consumer devices, including popular smartphones and smartwatches, already use Skylo’s services for satellite SOS and messaging, supported by a growing base of partners and activated users.

The focus of the talk was on why NB-NTN voice matters and why the timing is right. Geostationary satellites are already in orbit with vast coverage footprints, and 3GPP has been progressing work to support narrowband voice services in Release 20. One of the most important enablers is the arrival of very low bitrate AI-driven codecs that maintain high audio quality even at around 1 kbps. This is essential, because narrowband satellite links have strict bandwidth constraints.

Soham also highlighted the benefits of using non-IP data delivery (NIDD) instead of traditional IP traffic. For narrowband systems, removing unnecessary IP and UDP overhead provides significant efficiency gains, especially when compared with robust header compression. Skylo’s approach combines these efficiencies with a dedicated voice gateway that allows operators to continue using their existing SIP-based infrastructure while the device communicates over the satellite link using I1 protocol messages. This keeps the signalling footprint small and improves call setup times. While SIP usually requires many transactions to establish a call, I1 can achieve the same outcome in only a few messages, which is particularly valuable on long-latency satellite links.

The talk also touched on current 3GPP work to refine signalling and user-plane support for NB-NTN voice over GEO systems. There is ongoing activity in Service Architecture (SA) Group 2 on improvements that reduce delays and optimise both SIP and I1-based procedures for satellite conditions. A number of companies, including Skylo, are contributing to this effort.

Soham concluded with a demonstration of Skylo’s voice architecture as it operates today. Using a standard NTN-capable handset, Skylo’s core network and its voice gateway, calls can be delivered to a SIP client through an operator’s existing infrastructure. This shows that narrowband satellite voice is no longer experimental. It is already functioning in real systems and is moving rapidly towards broader adoption.

You can watch the full talk from the workshop below.

Related Posts

Comments

Popular posts from this blog

Laser Inter-Satellite Links (LISLs) in a Starlink Constellation

When we first talked about Starlink back in 2019 , we saw in the video that the concept involved laser communication to communicate between the satellites. While the initially launched satellites did not have the laser communication mechanism built in, it looks like they are being added to the newer ones.  A report from Fast Company in late 2021 said: One of the next big upgrades in telecom will involve satellites firing lasers at each other—to beam data, not blow stuff up. The upside of replacing traditional radio-frequency communication with lasers, that encode data as pulses of light, can be much like that of deploying fiber-optic cable for terrestrial broadband: much faster speeds and much lower latency. “Laser links in orbit can reduce long-distance latency by as much as 50%, due to higher speed of light in vacuum & shorter path than undersea fiber,” SpaceX founder Elon Musk tweeted in July about the upgrade now beginning for that firm’s Starlink satellite constellation. ...

IEEE 802.11bn Ultra High Reliability (UHR), a.k.a. Wi-Fi 8

Back in 2020 we looked at the introductory post of Wi-Fi 7 which was followed up by a more detailed post in Feb 2022. We are now following on with an introductory post on the next generation Wi-Fi.  A new paper on arXiv explores the journey towards IEEE 802.11bn Ultra High Reliability (UHR), the amendment that will form the basis of Wi-Fi 8. Quoting selected items from the paper  below: After providing an overview of the nearly completed Wi-Fi 7 standard, we present new use cases calling for further Wi-Fi evolution. We also outline current standardization, certification, and spectrum allocation activities, sharing updates from the newly formed UHR Study Group. We then introduce the disruptive new features envisioned for Wi-Fi 8 and discuss the associated research challenges. Among those, we focus on access point coordination and demonstrate that it could build upon 802.11be multi-link operation to make Ultra High Reliability a reality in Wi-Fi 8. The IEEE 802.11bn UHR: Whose ...

How Do Apple AirTags Work?

Apple AirTags have steadily gained popularity in the smart tag market. A recent report highlighted that 69% of smart tag buyers in late 2024 chose an Apple AirTag. This marks a significant rise from 45% in early 2022. In contrast, Tile, the category pioneer now owned by Life360, has seen its market share fall to 11% from 17% during the same period. Samsung's Galaxy SmartTags now hold second place. Interestingly, the technology behind AirTags resembles concepts like Opportunity Driven Multiple Access (ODMA) or Multihop Cellular Networks (MCNs), which I have previously explored . A similar approach has also been discussed regarding Bluetooth-based Ad-Hoc networks . How Do They Work? AirTags primarily use Bluetooth Low Energy (BLE) to communicate with nearby Apple devices that are part of the Find My network. This vast network consists of millions of Apple devices, including iPhones, iPads, and Macs, which can detect AirTags and securely relay their location back to the owner. Addit...