1. Centre for Mobile Computing, Institute of Information
and Mathematical Sciences, Massey University, Private Bag 102 904, NSMC, Auckland,
New Zealand,
2. Centre for Mobile Computing, Institute of Information
and Mathematical Sciences Information and Mathematical Sciences, Massey University,
Private Bag 102 904, NSMC, Auckland, New Zealand,
3. Centre for Mobile Computing, Institute of Information
and Mathematical Sciences Information and Mathematical Sciences, Massey University,
Private Bag 102 904, NSMC, Auckland, New Zealand