Introduction

Document Version 1.8: Nov 13, 2023

SMP Protocol Version: 2

Skylo offers a global geostationary satellite NB-IoT network, leveraging the standardized 3GPP ecosystem to offer seamless hybrid connectivity for LPWAN use cases. Device manufacturers and providers of wireless IoT solutions can leverage Skylo’s network to extend the reach of traditional cellular IoT solutions to include satellite coverage that is always-on and available anywhere devices can see the sky. This hybrid cellular / satellite connectivity is available using standard cellular IoT device hardware with a firmware update to expand coverage to include satellite.

This document is to guide device manufacturers with requirements, usage policies and best practices for designing devices and solutions that will operate on Skylo’s satellite network.

Requirements ensure devices on the Skylo network are compliant with all applicable regulations, and operate in a manner compatible with Skylo’s systems
Policies describe usage limits and patterns for device application behavior necessary to maintain acceptable performance for all customers of the service
Best practices provide suggestions for device configuration and application design to make optimal use of the Skylo network, resulting in the best possible experience for end users of the service

Skylo will provide a certification to devices which have demonstrated compliance with the stated requirements, enabling these devices to access Skylo’s satellite NB-IoT network.

Chipset Requirements

For a device to be compatible with Skylo’s NB-IoT satellite network service, it must contain a Skylo certified NB-IoT release version. At a minimum, the chipset should support Rel-14 with select Non-Terrestrial Network (NTN) features from Rel-17 . Please contact the Skylo Device Certification Team for a complete list of Skylo certified chipsets/modules ([email protected]).

Radio Frequency Performance Requirements

Operating Bands

The Skylo satellite network operates across a multitude of satellite and spectrum deployment configurations. The services are deployed across geostationary satellites on a global basis utilizing Band 23, 255, and 256 as seen in Table 1:

Band	FWD (UE Rx)	RTN (UE Tx)	Separation	Region
Band 255	1525-1559 MHz	1626.5-1660.5 MHz	-101.5 MHz	Global
Band 256	2170-2200 MHz	1980-2010 MHz	190 MHz	Europe
Band 23	2180-2200 MHz	2000-2020 MHz	180 MHz	North America

^{Table 1. Skylo deployment band configuration}

Radiating Power and Sensitivity

Eligible devices are classified into two tiers, Type 1 devices and Type 2.

Type 1 NB-IoT Requirements: Free Space

Band	TRP (dBm)	TIS (dBm)
Band 255	≥ 20	≤ -112 dBm
Band 256	≥ 20	≤ -112 dBm
Band 23	≥ 20	≤ -112 dBm

^{Table 2. Type 1 device performance criteria}

Type 2 NB-IoT Requirements: Free Space

Band	TRP (dBm)	TIS (dBm)
Band 255	≥ 16	≤ -108 dBm
Band 256	≥ 16	≤ -108 dBm
Band 23	≥ 16	≤ -108 dBm

^{Table 3. Type 2 device performance criteria}^‍^{Annexure 1 - Please see annexure 1 to measure reference sensitivity}

As seen in Tables 2 and 3, a device is classified based upon its Total Radiated Power (TRP) and Total Isotropic Sensitivity (TIS).

Reference: https://www.gsma.com/newsroom/wp-content/uploads//TS.51-v2.0.pdf

Type 1 devices typically represent fixed asset monitors or industrial asset trackers with higher performing RF systems. Type 2 devices represent lower performing devices such as consumer electronics products including mobile handsets or wearables. Both categories of devices are eligible to access the Skylo network. However, service pricing may be based upon device type certification.

Device Classification

The device must be assigned to one of the following device classes in Table 4. The device must be assigned to the closest device class, but cannot exceed the parameters defined in the device class.Emission Designator Reference: https://fccid.io/Emissions-Designator/

ID	Frequency	Output Power EIRP (max)	Emission Designator	Modulation	Polarization
Class 1	Tx: 2000 - 2020 MHz Rx: 2180 - 2200 MHz	30 dBm	65K0G7D	BPSK/QPSK	Linear
Class 2	Tx: 2000 - 2020 MHz Rx: 2180 - 2200 MHz	30 dBm	195KG7D	BPSK/QPSK	Linear
Class 3	Tx: 2000 - 2020 MHz Rx: 2180 - 2200 MHz	23 dBm	65K0G7D	BPSK/QPSK	Linear
Class 4	Tx: 2000 - 2020 MHz Rx: 2180 - 2200 MHz	23 dBm	195KG7D	BPSK/QPSK	Linear
Class 5	Tx: 2000 - 2020 MHz Rx: 2180 - 2200 MHz	16 dBm	65K0G7D	BPSK/QPSK	Linear
Class 6	Tx: 2000 - 2020 MHz Rx: 2180 - 2200 MHz	16 dBm	195KG7D	BPSK/QPSK	Linear
Class 7	Tx: 2000 - 2020 MHz Rx: 2180 - 2200 MHz	30 dBm	65K0G7D	BPSK/QPSK	RHCP
Class 8	Tx: 2000 - 2020 MHz Rx: 2180 - 2200 MHz	30 dBm	195KG7D	BPSK/QPSK	RHCP
Class 9	Tx: 2000 - 2020 MHz Rx: 2180 - 2200 MHz	23 dBm	65K0G7D	BPSK/QPSK	RHCP
Class 10	Tx: 2000 - 2020 MHz Rx: 2180 - 2200 MHz	23 dBm	195KG7D	BPSK/QPSK	RHCP
Class 11	Tx: 2000 - 2020 MHz Rx: 2180 - 2200 MHz	16 dBm	65K0G7D	BPSK/QPSK	RHCP
Class 12	Tx: 2000 - 2020 MHz Rx: 2180 - 2200 MHz	16 dBm	195KG7D	BPSK/QPSK	RHCP
Class 13	Tx: 2000 - 2020 MHz Rx: 2180 - 2200 MHz	30 dBm	65K0G7D	BPSK/QPSK	LHCP
Class 14	Tx: 2000 - 2020 MHz Rx: 2180 - 2200 MHz	30 dBm	195KG7D	BPSK/QPSK	LHCP
Class 15	Tx: 2000 - 2020 MHz Rx: 2180 - 2200 MHz	23 dBm	65K0G7D	BPSK/QPSK	LHCP
Class 16	Tx: 2000 - 2020 MHz Rx: 2180 - 2200 MHz	23 dBm	195KG7D	BPSK/QPSK	LHCP
Class 17	Tx: 2000 - 2020 MHz Rx: 2180 - 2200 MHz	16 dBm	65K0G7D	BPSK/QPSK	LHCP
Class 18	Tx: 2000 - 2020 MHz Rx: 2180 - 2200 MHz	16 dBm	195KG7D	BPSK/QPSK	LHCP
Class 19	Tx: 1626.5 - 1660.5 MHz Rx: 1525- 1559 MHz	30 dBm	65K0G7D	BPSK/QPSK	Linear
Class 20	Tx: 1626.5 - 1660.5 MHz Rx: 1525- 1559 MHz	30 dBm	195KG7D	BPSK/QPSK	Linear
Class 21	Tx: 1626.5 - 1660.5 MHz Rx: 1525- 1559 MHz	23 dBm	65K0G7D	BPSK/QPSK	Linear
Class 22	Tx: 1626.5 - 1660.5 MHz Rx: 1525- 1559 MHz	23 dBm	195KG7D	BPSK/QPSK	Linear
Class 23	Tx: 1626.5 - 1660.5 MHz Rx: 1525- 1559 MHz	16 dBm	65K0G7D	BPSK/QPSK	Linear
Class 24	Tx: 1626.5 - 1660.5 MHz Rx: 1525- 1559 MHz	16 dBm	195KG7D	BPSK/QPSK	Linear
Class 25	Tx: 1626.5 - 1660.5 MHz Rx: 1525- 1559 MHz	30 dBm	65K0G7D	BPSK/QPSK	RHCP
Class 26	Tx: 1626.5 - 1660.5 MHz Rx: 1525- 1559 MHz	30 dBm	195KG7D	BPSK/QPSK	RHCP
Class 27	Tx: 1626.5 - 1660.5 MHz Rx: 1525- 1559 MHz	23 dBm	65K0G7D	BPSK/QPSK	RHCP
Class 28	Tx: 1626.5 - 1660.5 MHz Rx: 1525- 1559 MHz	23 dBm	195KG7D	BPSK/QPSK	RHCP
Class 29	Tx: 1626.5 - 1660.5 MHz Rx: 1525- 1559 MHz	16 dBm	65K0G7D	BPSK/QPSK	RHCP
Class 30	Tx: 1626.5 - 1660.5 MHz Rx: 1525- 1559 MHz	16 dBm	195KG7D	BPSK/QPSK	RHCP

^{Table 4. Device class parameters}

GNSS Access

The device must also have access to a local source of GNSS location information. This GNSS source may be internal to the NB-IoT chipset or it may also be external. If external, the device host application must be capable of providing GNSS location information to the NB-IoT modem via AT-command.

GNSS Metric	Value
95% CEP	≤ 100 m
Modem Interface	AT-Command
Data Format	NMEA

^{Table 5. GNSS Requirements}

Cellular Certification Requirements

At a minimum, PCS Type Certification Review Board (PTCRB ) certification is required This is a certification program established by leading wireless operators to define test specifications and processes to ensure device interoperability on global wireless networks. With PTCRB certification, operators and device manufacturers are confident of a device's interoperability with member mobile networks. PTCRB testing and certification is executed by PTCRB labs. For more information visit the PTCRB website .

Device Application Requirements

The following checklist represents a minimum set of requirements expected of application software running on devices that intend to connect into Skylo’s Satellite network.

Radio Access Technology

The modem chipset selected for the device should support NB-IoT Release 14+ with NTN features from 3GPP release 17. Please contact the Skylo Certification Team for the current certified chipset list.
The application software should set the modem to use NB-IoT radio access technology when searching for the Skylo Satellite bands.

GNSS

The device must have access to GNSS location data. The device can have either internal GNSS [ Modem Module supporting GNSS co-ex with NB-IoT ] or an external GNSS module connected with Host MCU.
The application should feed GNSS details through specified AT Commands to Modem in external GNSS operating mode.
- Ref: Please refer to AT Commands from chipset and module providers
The GNSS must have a valid fix prior to establishing connectivity

SIM

Skylo network service can be activated through your network service provider with appropriate service plans. The device is authenticated by a physical SIM or embedded SIM.
The device can have a physical SIM with either a single Profile (Skylo network profile or an M(V)NO profile) to enable satellite-only service or it could be a Multi-Profile SIM with the Skylo profile as one of them.
A device using a multi-profile SIM would require switching between Skylo and terrestrial MNO/MVNO networks through supported network profiles. Each profile can have a different IMSI ( International Mobile Subscriber Identity ) or have the same IMSI depending on carrier agreements.
Embedded SIM [ eSIM ] should support a LPA (Local Profile Assistant) for Consumer versions so that a Skylo profile can be downloaded to it unless the eSIM comes pre-loaded with the Skylo profile. For industrial eSIMs, the Skylo profile will need to be “pushed”to the device from the SM-DP+ (RSP) server of MNO/MVNO owning the device.

Data Usage Policy and Best Practices

The Skylo network is designed with IoT data rates in mind. This is reflected in our network policies and associated data plans. Please ensure you have the correct data plan associated with your SIM.

Satellite transmission packet size and frequency should adhere to the following best practices:

The maximum packet size for each transmission is 256 bytes.
The minimum time between successive packets should greater than 30 seconds

The following network configurations are used on the satellite network:

c-edrx Enabled ( 2 Seconds)
I-edrx enabled and turned on to support a range of 10.24 secs to 2.182 hours (1024 hyper frames)
PSM > 24 hours

Depending on the data plan associated with a device and solution, real-time messaging and/or alerting may be supported. As a best practice when designing and implementing a solution that includes real time messaging and/or alerting, be sure application logic can accommodate standard message 1-way latency of up to 30 seconds.

Satellite enabled use cases are best served when devices have a clear view to the southern sky for users in the northern hemisphere and vice-versa..

Regulatory Licensing and Certifications

This section is for information purposes only and is not intended to provide any legal opinion or regulatory counsel on the topic of FCC licensing in the United States.

This section describes the FCC regulations that are applicable to portable ‘mobile earth terminal’ (MET) devices providing mobile satellite service (MSS).

Industry Certification

At a minimum, the UE should be certified by the PCS Type Certification Review Board (PTCRB ). This is a certification program established by leading wireless operators to define test specifications and processes to ensure device interoperability on global wireless networks. With PTCRB certification, operators and device manufacturers are confident of a device's interoperability with member mobile networks. PTCRB testing and certification is executed by PTCRB labs.

Regulatory Conformance Specs

The section lists various standards and specifications with which devices need to demonstrate compliance in order to be certified to use NTN functionality by Test Houses

ETSI Standards

EN 301 681 - Harmonised Standard for Mobile Earth Stations (MES) of Geostationary mobile satellite systems, including handheld earth stations, for Satellite Personal Communications Networks (S-PCN) under the Mobile Satellite Service (MSS), operating in the 1,5 GHz and 1,6 GHz
- https://www.etsi.org/deliver/etsi_en/301600_301699/301681/02.01.02_60/en_301681v020102p.pdf
EN 302 574 (Part 3) - Harmonised Standard for Mobile Earth Stations (MES) operating in the 1 980 MHz to 2 010 MHz (earth-to-space) and 2 170 MHz to 2 200 MHz (space-to-earth) frequency bands Part 3: User Equipment (UE) for narrowband systems
- https://www.etsi.org/deliver/etsi_en/302500_302599/30257403/02.01.01_60/en_30257403v020101p.pdf
EN 301 489 - Electromagnetic Compatibility (EMC) standard for radio equipment and services; Part 20: Specific conditions for Mobile Earth Stations (MES) used in the Mobile Satellite Services (MSS)
- https://www.etsi.org/deliver/etsi_en/301400_301499/30148920/02.01.02_20/en_30148920v020102a.pdf

FCC Standards

FCC - PART 25 - SATELLITE COMMUNICATIONS
- Federal Register :: Request Access

Skylo Network Standards

Total Radiated Power (TRP) and Total Isotropic Sensitivity (TIS) at the upper and lower edges and midpoints of each NTN band (L-band and S-band) - testing methodology specified in 3GPP TR 37.902
- https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=2635

ETSI Compliance Test Cases

Test Case	Title	Testability
EN 301681 4.2.1	OOB unwanted emissions (carrier-on state)	Chipset-initiated: use AT commands to put device into continuously modulated mode and measure output on spectrum analyzer
EN 301681 4.2.2 EN 302 574-3 4.2.3	In-band unwanted emissions (carrier-on state)	Chipset-initiated: use AT commands to put device into continuously modulated mode and measure output on spectrum analyzer
EN 301681 4.2.3 EN 302 574-3 4.2.4	Unwanted emissions in carrier-off state	Chipset-initiated: use AT command to put modem into off state
EN 301681 4.2.4.1	Self-monitoring functions/Processor monitoring	Device-specific: reset or suspend device processor - device vendor to align test cases
EN 301681 4.2.4.2		Chipset function
EN 301681 4.2.4.3	Network control authorization	Connect to captive Base Stn - monitor that there is no output signal from device until it syncs with BS signal
EN 301681 4.2.4.4.1	Transmission disable/enable	Connect to captive Base Stn - demonstrate ability of BS to disable UE
EN 301681 4.2.4.4.2	Transmit frequency control	Connect to captive Base Stn - demonstrate ability of BS to set UE freq
EN 301681 4.2.4.5	Fellow radio stations in a dual-mode or multimode terminal	N/A - for multimode MES
EN 302 574-3 4.2.5.1	Absence of a valid network handling of output power
EN 302 574-3 4.2.5.2	Loss of signal handling of output power
EN 301681 4.2.5	Equipment identity: The MES shall be capable of transmitting its MES Identification Code upon reception of an appropriate NCF command addressed to it.
EN 301681 4.2.6	Protection of the radio astronomy service operation in the band 1660 MHz to 1 660,5 MHz and in the band 1 668,0 MHz to 1 670,0 MHz	[same as 4.2.4.4.1] Connect to captive Base Stn - demonstrate ability of BS to disable UE
EN 301681 4.2.7 EN 302 574-3 4.2.6	Receiver Adjacent Channel Selectivity	Connect via cable to captive Base Stn - activate adjacent channel +12 dB power relative to the desired channel, and read SINR of signal on desired channel using AT commands - requires device with antenna removed
EN 301681 4.2.8 EN 302 574-3 4.2.7	Receiver Blocking Characteristics	Connect via cable to captive Base Stn - activate CW signal 5MHz away from the desired channel and read SINR of signal on the desired channel using AT commands - requires a device with antenna removed
EN 301489-20 - 4.2	test conditions for MES	sufficient representative configurations of the MES

Annexure 1 - Reference Sensitivity for UE

The UE throughput shall be ≳95% of the maximum throughput of the reference measurement channel as specified in the below table.

Below are the fixed reference channel for receiver requirements (HD-FDD) without repetitions

Parameter	Unit	Value
Channel Bandwidth	MHz	0,2
Number of Subcarriers		12
Modulation		QPSK
Target Coding rate		1.3
Number of HARQ Processes	Processes	1
Maximum number of HARQ transmissions		1
Transport block size	Bits	88
Number of Sub-Frames per transport block		1
Transport Block CRC	Bits	24
Binary channel bits per Sub-Frame	Bits	320
LTE CRS Port		N/A
Number of NRS Port		1
Number of NPDSCH repetitions		0
UE DL Category		NB1

Glossary

LPWAN

Low Power Wide Area technology

Wireless wide area network technology that interconnects low-bandwidth, battery-powered devices with low bit rates over long ranges.

NB-IoT

NarrowBand-Internet of Things

Low-power wide-area network (LPWAN) technology standard that enables communication between devices that need to exchange small amounts of data over long periods of time.

IMSI

International Mobile Subscriber Identity

Number used to uniquely identify a mobile subscriber

EPC

Evolved Packet Core

Core Network defined for Packet Only Network(LTE) and majorly consists of MME, S-GW, P-GW

Device Conformance Document