Network APIs for Connectivity Quality

CAMARA Network Slice Booking

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This documentation is currently under development and subject to change. It reflects outcomes elaborated by 5G-MAG members. If you are interested in becoming a member of the 5G-MAG and actively participating in shaping this work, please contact the Project Office

Description

The "Network Slice Booking" API gives developers a programmable interface to reserve a network slice for a selected area and period, specifying the service time, the service area (a circle or a polygon) and a slice QoS profile (maximum number of devices, rate per device and delay budgets). The Network Slice Assignment API of the same project manages the assignment of devices to a booked slice.

A network slice is a logical network that provides specific network capabilities and network characteristics (for example a slice reserved for a live event). Booking a slice differs from the Quality on Demand API: QoD requests QoS for a single device's session on demand, whereas a slice reserves shared resources for an area and time window covering many devices. This API also overlaps with the Dedicated Networks API; see the Self-Assessment below.

Information: Network Slice Booking project page and GitHub repository

The API definitions can be obtained here: NetworkSliceBooking API_definitions folder

The Network Slice Booking API definition (YAML) is available at: network-slice-booking.yaml

Operations and dependencies

Network Slice Booking API

• POST /slices with a request body including serviceTime, serviceArea, sliceQosProfile, it is used to create a new network slice booking with the expected service time, service area, and QoS profile. The response contains a sliceId. If expected network slice resources are not available, the API consumer will receive an error response (CAMARA NetworkSliceBooking main@fc349ef network-slice-booking.yaml /slices POST (createSlice; 422 NETWORK_SLICE_BOOKING.RESOURCES_INSUFFICIENT); SliceAttributes).
• GET /slices/{sliceId} - query slice resource information details (CAMARA NetworkSliceBooking main@fc349ef network-slice-booking.yaml /slices/{sliceId} GET).
• DELETE /slices/{sliceId} - delete a Network Slice Booking (CAMARA NetworkSliceBooking main@fc349ef network-slice-booking.yaml /slices/{sliceId} DELETE).

Parameters describing a Network Slice QoS Profile

Parameter	Description
maxNumOfDevices	Is the maximum number of devices that can be connected to the slice. (CAMARA NetworkSliceBooking main@fc349ef network-slice-booking.yaml SliceQosProfile maxNumOfDevices)
downStreamRatePerDevice	Is the maximum downstream rate allowed for each device connected to the slice. (CAMARA NetworkSliceBooking main@fc349ef network-slice-booking.yaml SliceQosProfile downStreamRatePerDevice)
upStreamRatePerDevice	Is the maximum upstream rate allowed for each device connected to the slice. (CAMARA NetworkSliceBooking main@fc349ef network-slice-booking.yaml SliceQosProfile upStreamRatePerDevice)
downStreamDelayBudget	Is the maximum allowable downlink packet transmission latency (millisecond). (CAMARA NetworkSliceBooking main@fc349ef network-slice-booking.yaml SliceQosProfile downStreamDelayBudget)
upStreamDelayBudget	Is the maximum allowable uplink packet transmission latency (millisecond). (CAMARA NetworkSliceBooking main@fc349ef network-slice-booking.yaml SliceQosProfile upStreamDelayBudget)

Both rate parameters (downStreamRatePerDevice, upStreamRatePerDevice) indicate the individual device capability required for the slice. Both delay-budget parameters (downStreamDelayBudget, upStreamDelayBudget) share the same rationale: by limiting the delay, the network can provide an acceptable level of performance for various services, such as voice calls, video streaming, and data (CAMARA NetworkSliceBooking main@fc349ef network-slice-booking.yaml SliceQosProfile downStreamRatePerDevice, upStreamRatePerDevice, downStreamDelayBudget, upStreamDelayBudget).

Standardisation context

Network Slice Booking is a CAMARA API (OpenAPI 3.0.3). It exposes, at a booking-request level, what 3GPP defines as network slicing. In the 5G System a slice is identified by a Single Network Slice Selection Assistance Information value (S-NSSAI, TS 23.501 V20.3.0 clause 5.15.2.1) and is characterised, at management level, by a Network Slice Template. The management of slices (creation, allocation, deallocation) is covered by 3GPP slice management specifications, and the industry parameter template is the GSMA Generic Network Slice Template (GST). At runtime, the SEAL Network Slice Capability Enablement (NSCE) service exposes slice capabilities to vertical applications (TS 23.434 V20.1.0 clause 16; the detailed specification is TS 23.435, as referenced in TS 23.434 V20.1.0 clause 16.1).

The CAMARA network-slice-booking.yaml does not use this 3GPP nomenclature. It exposes independent, application-facing concepts (service time, a circular or polygonal service area, and a sliceQosProfile of per-device rates, delay budgets and a device count) rather than S-NSSAI, GST or URSP. The 3GPP terms above are therefore background, not a normative part of the API; the correspondence is 5G-MAG analysis and an operator may implement the booking differently.

The sliceQosProfile here is a separate parameter set from the operator-catalogue QoS Profiles API. It expresses aggregate slice dimensioning: a maxNumOfDevices and per-device upstream/downstream rate and delay budgets. Note that these are per-device maxima applied across an aggregate: as 5G-MAG's Self-Assessment observes, dimensioning for the peak per-device value across all devices can over-provision the slice. The booking is bound to an area and time, not to specific devices, which is the main structural difference from the device-oriented QoS APIs and the source of the open questions below (CAMARA NetworkSliceBooking main@fc349ef network-slice-booking.yaml SliceQosProfile; CAMARA QoSProfiles main@8ce8f4d qos-profiles.yaml).

---

Workflow: Media application using the QoS Network Slice Booking API

A user of a media application would like to book the availability of a network slice for a given time area and QoS Profile. The following steps are executed:

Step 0: Pre-conditions

• In principle none. Only after invoking the API the API consumer will receive a response whether the network slice booking can be successfully created (CAMARA NetworkSliceBooking main@fc349ef network-slice-booking.yaml /slices POST).

Step 1: Create a Network Slice Booking

• POST /slices passing the serviceTime, serviceArea and sliceQosProfile parameters (CAMARA NetworkSliceBooking main@fc349ef network-slice-booking.yaml /slices POST; SliceAttributes required serviceTime, serviceArea, sliceQosProfile).

---

5G-MAG's Self-Assessment

The Network Slice Booking API would be used prior to the start of the event to book resources for a given time, area and QoS profile. The booking applies to a service time and area, but it is not associated with a device. The QoS Profile is defined for an aggregation of devices, each of which is allowed a maximum downstream/upstream rate; this may assume a design of the resources for the peak values per device, which may result in overdimensioning resources. This API may also be redundant compared with the Dedicated Networks API (CAMARA NetworkSliceBooking main@fc349ef network-slice-booking.yaml SliceQosProfile downStreamRatePerDevice, upStreamRatePerDevice, maxNumOfDevices).

Potential improvements:

• For consistency, the definition of the QoS profile could leverage the qosProfile defined for other QoS-related APIs.
• The booking could be applied per device rather than to an aggregate of devices
• Devices are associated with a booked slice through the separate Network Slice Assignment API (network-slice-assignment.yaml), which assigns a device to an existing slice by sliceId and keeps the number of devices within maxNumOfDevices (CAMARA NetworkSliceBooking main@fc349ef network-slice-assignment.yaml info.description; /slices/{sliceId}/devices).

---

Network Slice Booking API Usage

With POST /slices and one of the two service-area shapes below (CAMARA NetworkSliceBooking main@fc349ef network-slice-booking.yaml SliceAttributes serviceArea; examples CREATE_CIRCLE, CREATE_POLYGON).

A location described as a circle (a centre point plus a radius in metres):

{
  "serviceTime": {
    "startDate": "2024-06-01T12:00:00Z",
    "endDate": "2024-06-01T12:00:00Z"
  },
  "serviceArea": {
    "areaType": "CIRCLE",
    "center": {
      "latitude": 45.754114,
      "longitude": 4.860374
    },
    "radius": 800
  },
  "sliceQosProfile": {
    "maxNumOfDevices": 5,
    "downStreamRatePerDevice": {
      "value": 10,
      "unit": "bps"
    },
    "upStreamRatePerDevice": {
      "value": 10,
      "unit": "bps"
    },
    "downStreamDelayBudget": {
      "value": 12,
      "unit": "Milliseconds"
    },
    "upStreamDelayBudget": {
      "value": 12,
      "unit": "Milliseconds"
    }
  }
}

or described as a polygon (an ordered list of boundary coordinates):

  "serviceArea": {
    "areaType": "POLYGON",
    "boundary": [
      {
        "latitude": 45.754114,
        "longitude": 4.860374
      },
      {
        "latitude": 45.753845,
        "longitude": 4.863185
      },
      {
        "latitude": 45.753916,
        "longitude": 4.866531
      },
      {
        "latitude": 45.754116,
        "longitude": 4.876353
      }
    ]
  },

Type of response: the booking attributes (serviceTime, serviceArea, sliceQosProfile) plus a sliceId identifying the booking (CAMARA NetworkSliceBooking main@fc349ef network-slice-booking.yaml /slices POST response 201; SliceInfo):

{
  "sliceId": "3fa85f64-5717-4562-b3fc-2c963f66afa6",
  "status": "REQUESTED"
}