/ImageGroup: The image group that contains the image to transmit using multicasting. If not specified and only one image ...

[/ImageGroup:]    The image group that contains the image to
                                    transmit using multicasting. If not
                                    specified and only one image group exists
                                    on the server, that image group will be
                                    used. If more than one image group
                                    exists on the server, then the image
                                    group must be specified.
[/Filename:]             If the source image cannot be uniquely
                                    identified by name, you must specify the
                                    file name.


EXAMPLES:
---------
To create an AutoCast transmission of a boot image:
WDSUTIL /New-MulticastTransmission /FriendlyName:"WDS Boot Transmission"
/Image:"X64 Boot Image" /ImageType:Boot /Architecture:x64
/TransmissionType:AutoCast


To create an AutoCast transmission of an install image:
WDSUTIL /New-MulticastTransmission /FriendlyName:"WDS AutoCast Transmission"
/Image:"Vista with Office" /ImageType:Install /TransmissionType:AutoCast


To create a ScheduledCast transmission of an install image:
WDSUTIL /New-MulticastTransmission /FriendlyName:"WDS SchedCast Transmission"
/Server:MyWDSServer /Image:"Vista with Office" /ImageType:Install
/TransmissionType:ScheduledCast /Time:"2006/11/20:17:00" /Clients:100