Page 130 - ITU Kaleidoscope 2016

Authorized
public Infrastructure Provider IoT Directory Service Provider
directory Resource
Update allocation Records storage &
replication
Record Record
cache cache Type Amount Place Lookup (scheduling)
Update
Update
Replica Load statistics and
Resource request
performance metrics
Update Ack Resource Controller
Load statistics
IoT device Performance prediction

Figure 5. Record update
Figure 6. Resource allocation
statistics and performance metrics from the IoT directory
4.4. Record Update service system and estimates required amount of resources
As mentioned earlier, an update request originates either to achieve the target performance levels. Accordingly, it
from the record owner IoT device that changes its sends a resource request containing the description of
parameters due to an event (e.g. changing location due to required resources to the infrastructure provider. The
mobility, adding a sensor to the IoT device to generate a infrastructure provider analyzes the resource request and
new type of data, or changing certificates and keys for reserves appropriate types and amount of resources in
security enhancement) or from the network (e.g. proxy appropriate places. The resources are allocated to the IoT
gateway) that monitors the new parameters being assigned directory service provider. This close loop operation among
to or associated with the IoT device. As shown in Figure 5, the resource controller, infrastructure provider and IoT
the update request is sent to the anchor cache server to directory service provider guarantees that the performance
update its local cache copy. The cache server verifies the is always met in spite of the workload and network
message authenticity, updates the record stored in it (and its condition fluctuations.
replicas) to minimize the time of record inconsistency in the
locality, and forwards the update request to the authorized 5. CONCLUSION
public directory. If the record has been stored in more than
one cache servers, the authorized public directory server We presented the architectural design of a novel IoT
updates all the caches (known from the trackable cache directory service, which is capable to store and provide
list). dynamic records of a huge number of IoT devices. We
described the components and processes involved in the
Alternatively, if the other cache servers have obtained the proposed IoT directory service architecture and outlined the
record copy from the anchor cache server, before scheme of security and privacy protection and on-demand
forwarding the update request to the authorized directory, adjustment of virtualized computational and network
the anchor cache server forwards the update request to the resources allocated to the IoT directory service so that its
other cache servers (as shown by a dotted arrow in the performance is maintained even when the workload
figure). To further minimize the signaling overhead, the fluctuates.
update requests flow in bundle (containing update
information of several IoT devices, e.g. in the event of In future work, we will design the resource allocation
group mobility) between the authorized public directory algorithm for the resource controller, implement the IoT
and cache servers. directory service in a testbed network, and study its
performance in detail by varying the workload and network
As update times are crucial, our proposal reduces the capacity. We will also gradually bring this research
number of elements involved to the minimum. At the same outcome to ITU for standardization.
time, it forwards any update to the first component that
knows where a copy of the record has been cached. This
simplifies the process of maintaining cache coherency, and REFERENCES
thus improves the overall performance of the system.
[1] ITU-T SG20: IoT and its applications including smart cities
4.5. Resource Allocation and communities (SC&C), http://itu.int/ITU-T/go/sg20.
Figure 6 shows the resource allocation and adjustment [2] V.P. Kafle, Y. Fukushima, and H. Harai, “Connecting the
world through trustable Internet of Things,” ITU
process involving the infrastructure provider, IoT directory Kaleidoscope Conference, 2015.
service provider, and resource controller. As mentioned
earlier, the resource controller regularly obtains load

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