# Service based (message) addressing

Norway uses a method called service based addressing (tjenestebasert adressering) to identify sender and receiver in message based communication regarding healthcare. This method is defined in three standards
- Tjenestebasert adressering del 1: Generelle krav (HIS 1153-1:2016)
- Tjenestebasert adressering del 2: Identifikatorer ved elektronisk samhandling (HIS 1153-2:2016)
- Tjenestebasert adressering del 3: Adressering (HIS 1153:2017)

## Solution proposal for service based addressing

The proposed solution is to include reference to HealthcareService in the no-basis-MessageHeader profile allowing a HealthcareService to be the layer of addressing in message based communication.

<img src="https://raw.githubusercontent.com/HL7Norway/basisprofiler-r3/master/Images/MessageHeader-HealthcareService.png" alt="Drawing" style="width: 100%;max-width: 1200px"/>

## Addressing in messaging AS-IS (for reference)

The model used in FHIR MessageHeader is to reference sender/receiver to either a Practitioner resource or a Organization resource. This model poses difficulties in a Service based addressing infrastructure.

<img src="https://raw.githubusercontent.com/HL7Norway/basisprofiler-r3/master/Images/MessageHeader-AS-IS.png" alt="Drawing" style="width: 100%;max-width: 1200px"/>