Unless otherwise agreed by the parties, the arbitral proceedings in respect of a particular dispute commence on the date on which a request for that dispute to be referred to arbitration is received by: (a) the institution nominated by the parties. Such a request must include a demand for arbitration that includes the contact details for the respondent to the arbitral proceeding; and the institution nominated by the parties, upon receipt of the request, shall notify the respondent of the receipt of the request for arbitration; or (b) the respondent, if no such institution referred to in Subsection (a) of this Section has been nominated by the parties.