"Environmental sensors include a wide array of sensors@ including those that monitor weather@ roadway surface@ water level@ and air quality conditions. These sensors are typically connected to a nearby microprocessor termed a Remote Processor Unit (RPU). An Environmental Sensor Station (ESS) consists of the RPU plus its suite of sensors. Typically@ this equipment is permanently located at a site along a travel corridor. In some cases@ the ""stations"" may be portable@ or even mobile. For the purpose of this standard@ all three types of stations are called ESS. In the transportation community@ these devices are frequently used in order to improve roadway maintenance and traffic operations. Environmental sensors are also frequently co-located with pavement treatment systems (PTS) and@ in fact@ may use the same controller. Thus@ for the purpose of this standard@ the term ESS may also include a PTS. NOTE??The PTS portion of this standard may be placed in a separate standard in the future. Unfortunately@ there have not been standards defining how these devices communicate with management systems. As a result@ each manufacturer has developed its own protocol to meet its own particular needs. This approach has resulted in systems that are not interchangeable or interoperable. If an agency wishes to use either a central management system or additional ESS from a different vendor@ the agency encounters significant systems integration costs. This additional cost inhibits information sharing within and between various potential users of the data and prevents vendor independence. Without vendor independence@ costs further increase because of a lack of a competitive market. These problems have not been limited to weather and environmental monitoring. Many other devices also need to exchange information. In surface transportation@ examples include traffic signal controllers@ dynamic message signs@ bus priority sensors@ etc. To address these problems@ the NTCIP is developing a family of open standards for communications between field devices and central management systems. This standard is a part of that larger family and is designed to define an interoperable and interchangeable interface between a transportation management system and an ESS while still allowing for extensions beyond this standard to allow for new functions as they may be needed. It is expected that this will support the deployment of ESS from one or more vendors in a consistent and cost-efficient way. This standard only addresses a subset of the requirements required for procurement. It does not address requirements related to the performance of the sensors (e.g.@ accuracy@ the supported detection range@ the time it takes to detect conditions@ etc.)@ hardware components@ mounting details@ etc. This standard standardizes the communications interface by identifying the various operational needs of the users (Section 2) and subsequently identifying the requirements (Section 3) that must be supported for each need. The standard then defines the NTCIP standardized communications interface used to fulfill these requirements by identifying the dialogs (Section 4) and related data concepts (Section 5) that must be supported for each requirement. The traceability among the various sections is defined by the Protocol Requirements List (section 3.3) and the Requirements Traceability Matrix (Annex A). Conformance requirements for this standard are provided in section 3.3. An implementation of this standard requires lower level services to structure@ encode@ and exchange the data concepts defined by this standard. This standard assumes that the data concepts will be exchanged by one of the protocols defined in NTCIP 2301. "