Question on Packet format in 802.11

[gdeora]

Hi,

I have been wacking my brains over this for sometime
now. Hopefully, my problem will be obvious to many on
the list.

1. The MAC layer in 802.11 specifies a header size of
34 bytes (THE CRC filed is included in the header
length), while the frame body specifies a maximum size
of 2312 bytes. Thus the total size of the packet at
MAC layer is (2312 + 34 = 2346) bytes.

Now, for FHSS, at the physical layer, the maximum
payload allowed in PPSU is 4095 bytes (which will be
always greater than MAC packet size). So why have the
maximum size of 4095 bytes for the PPSU since the
physical layer will always be able to carry a MPSU
with a max. size of 2346 bytes?

2. One of the technical papers I read suggested that
for DSSS, the maximum packet size permissible at
Physical layer was 1023 bytes. I searched the
standards but could not find this explicitly mentioned
anywhere. Can someone kindly throw more light on this
or point where the above parameter is specified?

Thanking you people in advance.
Regards,
Gautam