| Internet-Draft | DLEP Power Constraints Extension | August 2026 |
| Rogge | Expires 22 February 2027 | [Page] |
This document defines an extension to the Dynamic Link Exchange Protocol (DLEP) to provide dynamic power constraints to the radio.¶
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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.¶
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:¶
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.¶
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 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:¶
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 | +-+-+-+-+-+-+-+-+
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) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The Flags field is defined as:¶
0 1 2 3 4 5 6 7 +-+-+-+-+-+-+-+-+ | Reserved |A| +-+-+-+-+-+-+-+-+
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:¶
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) | +-+-+-+-+-+-+-+-+
The Flags field is defined as:¶
0 1 2 3 4 5 6 7 +-+-+-+-+-+-+-+-+ | Reserved |A| +-+-+-+-+-+-+-+-+
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.¶
As described below, IANA has assigned two values per this document. Both assignments are to registries defined by [RFC8175].¶
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 |
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:¶
| Type Code | Description |
| TBD | Omnidirectional Power Constraints |
| TBD | Planar Power Constraints |
| TBD | Spherical Power Constraints |