(4) In the fog layer, a local gateway must notify other available
gateways about the presence of mobile sensors in its domain.
The reason is that binding necessary updates about the
network must be performed by gateways rather than the
mobile sensors to unburden tiny sensors from performing
heavy tasks.
(5) Global addressing must be supported in mobility solutions.
Medical sensors must be addressable anytime needed
independent of their current locations. In healthcare IoT, it is
one of the main challenges to accomplish global connectivity
with the devices using the current Internet infrastructure.
(6) Header information and payloads regarding data messages
should be optimized carefully. This reduces fragmentation,
the transmission overhead of data messages, and latency
while roaming.
(7) Mobility solutions must be based on distributed storage
of patients’ medical information rather than conventional
centralized approaches to support fault tolerance.
(8) The authentication and authorization of medical sensors,
smart gateways and caregivers must be performed to ensure
the protection of resources, confidentiality, and integrity of
the medical information.
(9) Robust security solutions must be provided as healthcare
IoT requires ensuring the protection of patients’ medical
information. Security support can be provided by the AES
algorithm which is provided in the data link layer. However,
stronger mechanisms to guarantee patients’ privacy as well
as the security of their medical data can be offered by IPSec in
the network layer and DTLS in the transport layer.
(10) In real-time healthcare IoT, mobility detection must be agile
so that it avoids delays, jitter, and interruptions of the communication
during the data handover process. Data handover
procedures (on the evaluation of specific metrics) can be categorized
into two main groups: movement parameters and
communication parameters. The movement parameters are
based on the node position, and movement direction, and
velocity. Such parameters are difficult to capture in resourceconstrained
sensors made to collect just physiological parameters.
The second group utilizes the communication
parameters in order to handle the requirements for the handover
task. The wireless link between two devices can be
evaluated using two different metrics: the Received Signal
Strength Indicator (RSSI) and the Link Quality Indicator (LQI).