Identifier in the Internet of Thing (IOT)

• The term “identifier” is similar to the term “name”. A name does not change with location, in contrast to an “address”, which is intended to be used to refer to the location of a thing. IP addresses are used to route packets between end-systems. Emerging IoT service providers expect to rely on a convenient identifier space for the envisioned service, knowing that anything can be assigned an identifier – a physical object, person, place or logical object. 

• IP addresses identify nodes in the Internet and serve as locators for routing. IPv6 allows larger address space than IPv4. In the IoT a large identification space will be needed to cover the identification of the tremendous number of connected objects. A specific semantic of these identifiers will follow the application’s need. 

•  we can consider IPv6 address space to be used as an identifier space of objects, since IPv6 address space is supposed to be large enough to offer up to 223 addresses in a square meter. Unfortunately, defining an identifier is not only about the scalability of the identifier space but is also about the structure and meaning/semantic of the identifier. It is important that an identifier only plays the role of identification, so that even if the objects identified are mobile, the identifier remains the same. In the IP communication model, IP addresses play two roles: from a network point of view, they act as a locator for routing and from an application point of view they identify hosts for the duration of a communication session. This dual role is seen to be problematic due to increasing demands for mobility and the multi-homing of end-systems.
  

• EPCglobal first standardized the EPC identifier, followed by the International Standardization Organization (ISO). In addition to ISO and EPCglobal, the ubiquitous ID Center (uIDcenter) has defined a generic identifier called “ucode”, which is not only intended to identify physical objects but also extended to places and digital information.

• The Internet Research Task Force (IRTF) and the Internet Engineering Task Force (IETF) have developed the host identity protocol (HIP), which defines host identifiers that can perform the identifier role of the IP address. This leaves the IP address to act solely as a locator for routing. These host identifiers of HIP protocol could potentially be used as another type of identifier in the IoT under the condition that they respect the ISO standard and are capable of carrying the semantic of the identifier needed by the intended IoT application.
  

• In order to use ONS for all the emerging IoT services orchestrating identifiers, certain problems, such as the scalability of this naming service, also has to be addressed since we are expecting billions of objects to be tagged with identifiers. Other non-technical issues related to ONS, such as the governance of this ONS, are also important. As for the DNS root, which is hosted in the United States, the ONS system will also have an ONS root, which Europe would like to host. Using the DNS approach in certain IoT services has led to World Object Web, the application running over the network or web of objects, similar to the World Wide Web running over the network of IP nodes; the Internet.