Aerospace and Electronic Systems Magazine May 2018 - 61

Jayousi et al.

Security and emergency. Solutions that are characterized by
the integration of CubeSat can be beneficial in the four different phases of the management of emergency situations
[23] in order to deliver information both to the stakeholders and to the population: these capabilities are absolutely
crucial both in catastrophic events and in terroristic attacks.

It is worth stressing that the considered services are mainly
broadcast ones; even if the provision of such services is now being
conceived for the portable UT, as described in the previous section, future diffusion of the considered broadcast services could
open the way to solutions tailored for hand-held devices (e.g. a
Smartphone).

CASE STUDY: ALERT MESSAGES BROADCASTING
The objective of this section is to show the applicability of the
proposed system to an Emergency scenario. Starting from the architecture that has been previously defined, an Alert Messaging
System which is able to efficiently deliver alert messages over
the incident area, has been designed and developed: the building
blocks of the broadcast architecture and their integration have been
introduced in [24], [25]. In the following subsections the implemented Alert Messaging System is described, providing an overview of the experimental activity carried out in the framework of
the D-SAT Mission.

EXPERIMENTAL ACTIVITY FRAMEWORK: THE D-SAT
MISSION

On the other hand, the objective of the Decommissioning Device Experiment was to demonstrate the in-orbit capabilities of
the D-Orbit Decommissioning device, that was responsible for the
management and control of the satellite during the disposal phase.
In fact, at the end of the mission, the Decommissioning Device
safely completed the activation procedure and the Solid Rocket
Motor was fired correctly.

MAMES PROTOCOL MAIN FEATURES
A comprehensive understanding of the different components of the
developed Alert Messaging System requires a brief overview of
the Multiple Alert Message Encapsulation over Satellite (MAMES) protocol main features [27], [28] and, in particular, of the
MAMES frame structure. MAMES Message (Figure 4) consists of
a set of headers and a payload, which comprises a concatenation of
Alert Protocol Messages.
The MAMES Headers comprise: the Mandatory Header (MH),
the Extension Headers (EHs), and the Alert Message Header
(AMH). MH and EHs contain mandatory and optional/enhancing
information, respectively, related to the entire MAMES Message.
For each Alert Protocol Message (AM) contained in the payload, a
corresponding AMH is defined, specifying the type, language, and
length of the AM it refers to.
Focusing on the proposed Alert Messaging System, the definition of the priority and time validity information encoded in the
MAMES Header fields is needed to introduce the MAMES Message processing performed on board of the CubeSat (D-SAT). In
detail:

C the MAMES Transport Priority field of the MH manages
The proposed Alert Messaging System has been developed and
the MAMES Frame priority with respect to other MAMES
implemented and the overall transmission-reception chain has
Frames at transport level;
been experimented in the framework of the D-SAT Mission (SatAlert Experiment) [26]. D-SAT spacecraft (previously described)
C the MAMES Validity Start and End fields indicate the time
has been designed and manufactured by D-Orbit and was launched
instant when the MAMES Frame shall become valid and inby the Polar Satellite Launch Vehicle (PSLV) in LEO Sun-Synvalid, respectively.
chronous Orbit at 500 km altitude in June 2017. The Mission main
experimental activities have been the SatAlert Experiment and the
THE ALERT MESSAGING SYSTEM
Decommissioning Device in-orbit technology validation.
The objective of the SatAlert experiment was to demonThe high-level design of the Alert Messaging System developed
strate the feasibility of both the transmission over the space
for the proof of concept of alert messages generation, broadcastsegment (LEO satellite)
of alert messages encapsulated into MAMES
(Multiple Alert Message
Encapsulation over Satellite) protocol messages
[27], [28] and their reception and decoding by
a portable SDR UT. All
the system components
have been validated,
including the on-board
software that parses and
broadcasts the MAMES Figure 4.
messages [29].
MAMES message structure: Header and payload.

MAY - JUNE 2018

IEEE A&E SYSTEMS MAGAZINE

Table of Contents for the Digital Edition of Aerospace and Electronic Systems Magazine May 2018