NS-2 Wireless Trace Format Takes More Space

I tried NS-2 wireless trace format as I needed to test python scripts which does not work on old wireless format. The same tcl file is used to generate new trace. When then old format is used, trace file size is 6,113 KB. It becomes 14,801 KB in the case of new trace. It is more than 2 times. It is probably the best to use the old format if the resource is limited. I did not do a proper research as I did was create a tcl file, use both trace files, compare sizes.