IEEE Consumer Electronics Magazine - January/February 2020 - 25

Figure 2. Proposed framework's block diagram.

Discovery, On-Boarding, Commissioning, and
Device Binding
This module consists of the following submodules: gateway-initiated discovery, device-initiated
discovery, device resource registration, onboarding and commissioning, and device binding.
Gateway-Initiated Discovery: If a gateway
wants to discover available resources, the gateway initiates the discovery process through the
gateway-initiated discovery submodule. This
module instructs the underlying communication
stacks to initiate the discovery process in their
respective networks. A separate discovery message is transmitted in each network. The gateway can either transmit a general discovery
message or a filter discovery message. In the
general message, the gateway does not use any
filter query, thereby indicating its interest in discovering all the resources available on devices
in different networks. In the filter message, a
query is transmitted with the discovery message
and a device in a particular network only responds to the message if it has a resource that
matches the query. For example, the gateway
may initiate a discovery process in a network to
discover resources with a temperature sensor.
Only devices with a temperature sensor
resource respond to the message. IoT-Connect
uses the discovery process standardized by the
underlying communication standards, therefore,
when a response for the discovery message is
received at the gateway, the gateway-initiated
discovery submodule converts the received
resource representation into our framework's
uniform resource representation format, and

January/February 2020

stores the information in a resource directory. It
is worth mentioning here that, if an underlying
standard allows to transmit security settings
and access rights in a response to a discovery
request, it is also handled by our framework. A
resource in any network can be uniquely identified by a universal resource identifier (URI), and
different networks can use different formats for
the URI. IoT-Connect's resource directory, uses
the following URI format to identify resources:
iof://technology-identifier:network-layer-address:
end-point/resource-type/resource-name.
Device-Initiated Discovery: For communication and control, the devices in a network also
need to find out about the available resources in
other networks within the HAS. Therefore, a
device can also initiate the following types of discovery request: general and filtered. The device
transmits one of the mentioned requests to the
gateway. On receipt of the discovery message,
the gateway consults the URI mapping register
corresponding to the communication standard
on which the request is received and its device
information base. Based on the security settings,
access rights, and the type of discovery request
the gateway sends an appropriate response to
the requesting device.
Resource Registration: There are scenarios
when a device explicitly registers its resources
with a gateway, such as at the time of joining a
network. If a communication standard allows
a device to explicitly register its resources, the
device can send an appropriate message for
resource registration to a gateway, and the
gateway handles the message in a similar way

IEEE Consumer Electronics Magazine - January/February 2020

Table of Contents for the Digital Edition of IEEE Consumer Electronics Magazine - January/February 2020