Manet H.R. Rogge Internet-Draft Fraunhofer FKIE Intended status: Standards Track 21 August 2026 Expires: 22 February 2027 DLEP Power Constraints Extension draft-rogge-manet-dlep-power-constraints-00 Abstract This document defines an extension to the Dynamic Link Exchange Protocol (DLEP) to provide dynamic power constraints to the radio. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on 22 February 2027. Copyright Notice Copyright (c) 2026 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/ license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Rogge Expires 22 February 2027 [Page 1] Internet-Draft DLEP Power Constraints Extension August 2026 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2 3. Extension Usage and Identification . . . . . . . . . . . . . 3 4. Data Items . . . . . . . . . . . . . . . . . . . . . . . . . 3 4.1. Omnidirectional Power Constraints Data Item . . . . . . . 3 4.2. Planar Power Constraints Data Item . . . . . . . . . . . 4 4.3. Spherical Power Constraints Data Item . . . . . . . . . . 5 5. Security Considerations . . . . . . . . . . . . . . . . . . . 7 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 6.1. Extension Type Value . . . . . . . . . . . . . . . . . . 7 6.2. Data Item Value . . . . . . . . . . . . . . . . . . . . . 7 7. Normative References . . . . . . . . . . . . . . . . . . . . 8 8. Informative References . . . . . . . . . . . . . . . . . . . 8 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 8 1. Introduction The Dynamic Link Exchange Protocol (DLEP) is defined in [RFC8175]. 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. 2. 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 [RFC2119]. 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). Rogge Expires 22 February 2027 [Page 2] Internet-Draft DLEP Power Constraints Extension August 2026 Power Transmission power density of the radio measured in dBm/Hz from -128 to 127. 3. 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 [RFC8175]. 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 Section 6.1. 4. 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. 4.1. 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. Rogge Expires 22 February 2027 [Page 3] Internet-Draft DLEP Power Constraints Extension August 2026 This data item MUST NOT be used more than once. The format of the Power Constraints Data Item is: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Data Item Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Power | +-+-+-+-+-+-+-+-+ Figure 1 Data Item Type: TBD Length: 1 Power: Maximum allowed power to transmit in dBm/Hz as a signed integer 4.2. 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: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Data Item Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Minimum Azimuth | Maximum Azimuth | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Azimuth Steps | Flags | Power (1) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Power (2) | ... | Power (a) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2 Data Item Type: TBD Rogge Expires 22 February 2027 [Page 4] Internet-Draft DLEP Power Constraints Extension August 2026 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: 0 1 2 3 4 5 6 7 +-+-+-+-+-+-+-+-+ | Reserved |A| +-+-+-+-+-+-+-+-+ Figure 3 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. 4.3. 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: Rogge Expires 22 February 2027 [Page 5] Internet-Draft DLEP Power Constraints Extension August 2026 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Data Item Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Mininmum Azimuth | Maximum Azimuth | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Mininmum Inclination | Maximum Inclination | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Inclination Steps | Azimuth Steps | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Flags | Power (1,1) | Power (2,1) | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Power (a,1) | ... | Power (a,2) | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Power (a,i) | +-+-+-+-+-+-+-+-+ Figure 4 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: 0 1 2 3 4 5 6 7 +-+-+-+-+-+-+-+-+ | Reserved |A| +-+-+-+-+-+-+-+-+ Rogge Expires 22 February 2027 [Page 6] Internet-Draft DLEP Power Constraints Extension August 2026 Figure 5 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. 5. Security Considerations The extension introduces a new Data Item for DLEP. The extension does not inherently introduce any additional vulnerabilities above those documented in [RFC8175]. The approach taken to security in that document applies equally when running the extension defined in this document. 6. IANA Considerations As described below, IANA has assigned two values per this document. Both assignments are to registries defined by [RFC8175]. 6.1. 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" [RFC8126] policy: +------+-------------------+ | Code | Description | +------+-------------------+ | TBD | Power Constraints | +------+-------------------+ Table 1: New Extension Type Value 6.2. 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" [RFC8126] policy: Rogge Expires 22 February 2027 [Page 7] Internet-Draft DLEP Power Constraints Extension August 2026 +-----------+-----------------------------------+ | Type Code | Description | +-----------+-----------------------------------+ | TBD | Omnidirectional Power Constraints | +-----------+-----------------------------------+ | TBD | Planar Power Constraints | +-----------+-----------------------------------+ | TBD | Spherical Power Constraints | +-----------+-----------------------------------+ Table 2: New Data Item Value 7. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC8175] Ratliff, S., Jury, S., Satterwhite, D., Taylor, R., and B. Berry, "Dynamic Link Exchange Protocol (DLEP)", RFC 8175, DOI 10.17487/RFC8175, June 2017, . 8. Informative References [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, June 2017, . Author's Address Henning Rogge Fraunhofer FKIE Fraunhofer Strasse 20 53343 Wachtberg Germany Email: henning.rogge@fkie.fraunhofer.de Rogge Expires 22 February 2027 [Page 8]