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Routing Manet DLEP PHY TLV This document defines an extension to the Dynamic Link Exchange Protocol (DLEP) to provide dynamic power constraints to the radio.

Introduction The Dynamic Link Exchange Protocol (DLEP) is defined in . It provides the exchange of link-related control information between DLEP peers. DLEP peers are comprised of a modem and a router. DLEP defines a base set of mechanisms as well as support for possible extensions. This document defines one such extension.

Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in . Additionally, this specification uses the following terminology:

Azimuth

Horizontal direction expressed as the angular distance between the direction of a fixed point and the direction of the object in degree from -180 (left) to +180 (right). Either measured relative to the antenna of the radio or relative to true North (routers choice).

Inclination

Vertical direction expressed as the angular distance between a fixed plane and the direction of the object in degree from -90 (down) to +90 (up). Either measured relative to the antenna of the radio or relative to the flat horizon (routers choice).

Power

Transmission power density of the radio measured in dBm/Hz from -128 to 127.

Extension Usage and Identification The use of the Power Contraints Extension SHOULD be configurable. To indicate that the Power Constraints Extension is to be used, an implementation MUST include the Power Constraints Extension Type Value in the Extensions Supported Data Item. The Extensions Supported Data Item is sent and processed according to . If the directional power constraints are used relative to the antenna, it is assumed that the routers system integrator is aware of the antennas orientation. The Power Constraints Extension Type Value is TBD; see .

Data Items All three data items of this extensions are meant to be used when power constraints are highly dynamic and must be changed and adapted on the fly by the router. All three data items are meant to be used in a Session Initialization and Session Update Message to define constraints for all outgoing transmissions. TODO: what is about defining destination specific constraints with a Request Link Characteristic Message? If the router requests a power contraints based on true north/horizon instead of relative to the radio antenna but the modem (radio) does have no capability tracking its orientation, the modem MUST deny the routers request. TODO: specify how the request is denied exactly If both unidirectional, planar and or spherical Power Constraints are defined the unidirectional TLV provides a default value for the planar TLV and the planar TLV provides a default value for the spherical TLV.

Omnidirectional Power Constraints Data Item Omnidirectional Power Constraints Data Item contains the maximum power the radio is allowed to transmit in any direction from its antenna. This data item MUST NOT be used more than once. The format of the Power Constraints Data Item is:

Data Item Type:

TBD

Length:

1

Power:

Maximum allowed power to transmit in dBm/Hz as a signed integer

Planar Power Constraints Data Item Planar Power Constraints Data Item contains the maximum power the radio is allowed to transmit described in discrete intervals of direction. If this data item is used more than one it MUST NOT contain overlapping intervals between the TLVs. The format of the Planar Power Constraints Data Item is:

Data Item Type:

TBD

Length:

variable

Minimum Azimuth:

Signed integer minimum azimuth angle of power constraints

Maximum Azimuth:

Signed integer maximum azimuth angle of power constraints

Azimuth Steps:

Number of discrete azimuth intervals of power constraints

Power (x):

Maximum allowed power in direction interval x from minimum to maximum azimuth in dBm/Hz as a signed integer

The Flags field is defined as:

A:

Absolute Flag, indicating that the azimuth is relative to true North. If not set the direction is relative to the radios antenna with a radio defined orientation.

Reserved:

MUST be zero. Left for future assignment.

Spherical Power Constraints Data Item Spherical Power Constraints Data Item contains the maximum power the radio is allowed to transmit described in discrete intervals of directions in both planar direction and elevation. If this data item is used more than one it MUST NOT contain overlapping areas between the TLVs. The format of the Spherical Power Constraints Data Item is:

Data Item Type:

TBD

Length:

variable

Minimum Azimuth:

Minimum Azimuth angle of power constraints

Maximum Azimuth:

Maximum Azimuth angle of power constraints

Minimum Inclination:

Minimum Inclination angle of power constraints

Maximum Inclination:

Maximum Inclination angle of power constraints

Azimuth Steps:

Number of discrete Azimuth intervals of power constraints

Azimuth Steps:

Number of discrete Inclination intervals of power constraints

Power (x,y):

Maximum allowed power in direction interval (x,y), with x refering to the Azimuth and y referring to the Inclination interval in dBm/Hz as a signed integer

The Flags field is defined as:

A:

Absolute Flag, indicating that the azimuth is relative to true North and the horizon. If not set the direction is relative to the radios antenna with a radio defined orientation.

Reserved:

MUST be zero. Left for future assignment.

Security Considerations The extension introduces a new Data Item for DLEP. The extension does not inherently introduce any additional vulnerabilities above those documented in . The approach taken to security in that document applies equally when running the extension defined in this document.

IANA Considerations As described below, IANA has assigned two values per this document. Both assignments are to registries defined by .

Extension Type Value IANA has assigned the following value in the "Extension Type Values" registry within the "Dynamic Link Exchange Protocol (DLEP) Parameters" registry. The new value is in the range with the "Specification Required" policy: New Extension Type Value

Code	Description
TBD	Power Constraints

Data Item Value IANA has assigned the following value in the "Data Item Type Values" registry within the "Dynamic Link Exchange Protocol (DLEP) Parameters" registry. The new value is in the range with the "Specification Required" policy: New Data Item Value

Type Code	Description
TBD	Omnidirectional Power Constraints
TBD	Planar Power Constraints
TBD	Spherical Power Constraints

Normative References In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. When routing devices rely on modems to effect communications over wireless links, they need timely and accurate knowledge of the characteristics of the link (speed, state, etc.) in order to make routing decisions. In mobile or other environments where these characteristics change frequently, manual configurations or the inference of state through routing or transport protocols does not allow the router to make the best decisions. This document introduces a new protocol called the Dynamic Link Exchange Protocol (DLEP), which provides a bidirectional, event-driven communication channel between the router and the modem to facilitate communication of changing link characteristics. Informative References Many protocols make use of points of extensibility that use constants to identify various protocol parameters. To ensure that the values in these fields do not have conflicting uses and to promote interoperability, their allocations are often coordinated by a central record keeper. For IETF protocols, that role is filled by the Internet Assigned Numbers Authority (IANA). To make assignments in a given registry prudently, guidance describing the conditions under which new values should be assigned, as well as when and how modifications to existing values can be made, is needed. This document defines a framework for the documentation of these guidelines by specification authors, in order to assure that the provided guidance for the IANA Considerations is clear and addresses the various issues that are likely in the operation of a registry. This is the third edition of this document; it obsoletes RFC 5226.