Coordinate this with the presiding officer and, if refreshments are to come after the meeting, announce that fact sometime during the meeting. If you do, program planners should assign someone to this task. If security guards are required, know this ahead of time. Also find out who pays for the guard service. This is especially true for displays and exhibits.
Security is important and can be expensive.
If a list of attendees is needed in advance for security purposes, be sure to prepare one. In advance, discuss with the presiding officer who will make the introductions. Ask for this information in the follow-up letter of confirmation. The introductory remarks should include the speaker's name and affiliation, past relevant experiences and educational background, publications and honors or awards, and any professional memberships. If an evaluation form is used, determine who will have copies at the program, who will distribute and pick them up, and who will analyze them.