u-blox A-GNSS User Manual

Product summary

AssistNow

u-blox A-GNSS services

Real-time online A-GNSS service with assured global availability

• Backed by our support and Quality of Service (QoS) guarantee

• Easy to integrate, even for products without SUPL compliance

• Data privacy protected from service to the enterprise

• Fast Time‑To‑First‑Fix

• Improved accuracy and position availability

• Lower power consumption

The challenges of stand-alone GNSS

GNSS users expect instant position information. With
standard positioning this is often not possible because at least
four satellites must be identied, and their complete orbital
position data (called Ephemeris)
received. Under adverse signal
conditions, data downloads from
the satellites to the receiver can
take minutes, hours or even fail
altogether. To cost‑eectively
fulll their mission, energy
constrained applications such as
battery operated IoT devices need
to last months or even years in the

eld. Lengthy or repeated attempts at data download can
quickly drain power and aect operations.

Assisted GNSS (A‑GNSS) accelerates calculation of position
by delivering satellite data such as Ephemeris, Almanac,
accurate time and satellite status to the GNSS receiver via
wireless networks or the Internet. This aiding data enables
a GNSS receiver to compute a position within seconds, even
under poor signal conditions. A‑GNSS provides faster Time‑
To‑First‑Fix and improved accuracy and position availability,
benets that directly translate to lower power consumption
and larger power autonomy.

AssistNow A-GNSS service description

AssistNow is u‑blox’s end‑to‑end A‑GNSS location service
that provides data in real time via AssistNow Online, as well as
predicted data via AssistNow Oine, and the two can either
be used alone or in combination. AssistNow boosts GNSS
acquisition performance and lowers power consumption for
devices with or without network connectivity.

AssistNow Online is a guaranteed globally-available real­time online A-GNSS service, an important distinction

that oers tremendous advantages to users in terms of
performance, availability, and reliability. The service works on
all standard mobile communication networks that support
Internet access, including GPRS, UMTS and Wireless LAN.
No special arrangements with mobile network operators are
needed, making this solution network‑operator independent
and globally available.

Guaranteed Quality of Service

AssistNow and all u‑blox services are delivered by the
Thingstream IoT service delivery platform. Thingstream is a
cloud‑based delivery platform and administration interface
for enterprise IoT services. The Thingstream platform
comprises IoT connectivity, security, enterprise‑grade MQTT
broker, visual programming, simple enterprise integration,
and support for u‑blox global positioning hardware.

At u‑blox we stand behind our services with the highest levels
of availability and delivery quality by providing full warranty,
support, and a Quality of Service (QoS) guarantee. The
technology building blocks are developed in‑house where we
have full ownership without the external dependencies that
can be barriers to responsiveness.

Easy to integrate, even without SUPL compliance

AssistNow A‑GNSS services require no additional hardware
and generate virtually no CPU load. The system is very easy
to implement and can be installed and operational within
a day. The advantage of easy integration extends also to
modems that lack SUPL compliance. With other solutions,
such modems have no access to assisted data. Adding to
the simplicity, u‑blox cellular modules feature an embedded
AssistNow client.

Data privacy protected from service to the enterprise

For select customers, AssistNow is also exclusively available
as a service‑to‑service (S2S) variant. With AssistNow S2S,
the privacy and condentiality of your data is safeguarded as
it proceeds directly from service to the enterprise. With IoT
data scenarios involving thousands if not millions of devices,
this protection has become a security imperative.

UBX‑13003352 ‑ R05

AssistNow

AssistNow Oine

Supports GPS and GLONASS
With AssistNow Oine, users download u‑blox’s Dierential

Almanac Correction Data from the Internet at their
convenience. The correction data is then transferred to the
mobile terminal via TCP/IP, serial port, memory card, etc, and
can either be stored in the GNSS receiver’s Flash EPROM
(if available) or in the memory of the application processor.
Therefore, the service requires no connectivity at system
start‑up and enables a position x within seconds, even
when no network is available.

u‑blox provides correction data valid from 1 to 35 days. The
size of these les increases with the length of the prediction
period, from as little as 3 kB to 125 kB. Positioning accuracy
decreases with the length of the correction data duration,
with 1–3 day data providing relatively high accuracy and 10–
35 day data progressively less accuracy. Regular updates
help to ensure a high level of position accuracy.

AssistNow Online

Supports GPS, Galileo, GLONASS, and BeiDou
With AssistNow Online, an internet‑connected GNSS device

downloads assistance data from u‑blox’s AssistNow Online
Service at system start‑up. The service works on all standard
mobile communication networks that support Internet
access, including GPRS, UMTS and Wireless LAN. No special
arrangements with mobile network operators are needed
to enable AssistNow Online, making this solution network
operator independent and globally available. u‑blox only
sends ephemeris data for those satellites currently visible to
the mobile device requesting the data, thus minimizing the
amount of data transferred.

u-blox products supporting AssistNow

All u‑blox GNSS receiver modules and chips
ALEX‑R5 series LTE‑M/NB‑IoT cellular SiP modules
SARA‑R5 series multi‑band LTE‑M/NB‑IoT cellular modules
SARA‑R4 series LTE‑M/NB‑IoT/EGPRS cellular modules
LARA‑R2 series LTE Cat 1 cellular modules
TOBY R2 series LTE Cat 1 cellular modules
SARA‑U2 series UMTS/HSPA cellular modules
LISA‑U2 series UMTS/HSPA cellular modules
SARA‑G4 series GSM/GPRS cellular modules
SARA‑G3 series GSM/GPRS cellular modules

AssistNow Online AssistNow Oine

Data

Data download frequency At every startup Once every X days

Data retrieval at start‑up Data downloaded from server Pre‑downloaded from local memory

Aiding data type Ephemeris, almanac, time, health Dierential almanac correction

Data validity period 2 ‑ 4 hours 35 days

Size of downloaded data 1 ‑ 3 kB 10 kB (1 day) ... 125 kB (35 days)

Acquisition (TTFF) performance As low as 1 second As low as 5 seconds

GNSS

Satellite systems supported

Further information

For contact information, see www.u-blox.com/contact-us.
For more product details and ordering information, see the product

data sheet.

UBX‑13003352 ‑ R05

GPS, Galileo, GLONASS, BeiDou GPS, GLONASS

Legal Notice:

u‑blox reserves all rights to this document and the information contained herein. Products,
names, logos and designs described herein may in whole or in part be subject to intellectual
property rights. Reproduction, use, modication or disclosure to third parties of this doc‑
ument or any part thereof without the express permission of u‑blox is strictly prohibited.

The information contained herein is provided “as is”. No warranty of any kind, either
express or implied, is made in relation to the accuracy, reliability, tness for a particular
purpose or content of this document. This document may be revised by u‑blox at any
time. For most recent documents, please visit www.u‑blox.com.
Copyright © 2021, u‑blox AG