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Dear TG1
Hello, I'm a graduated student in Korea. I read "Air interface
for fixed broadband wireless access systems" (IEEE 802.16.1-00_01r4, September
2000) and I have some question.
First, I can't understand registration contention. In
uplink subframe structure( Figure 53), there is Registration contention
slots(QAM-4). I think SS will send registration request message to BS in these
slots. But REG-REQ message isn't fixed. And it includes configuration file so it
is very long. So I think there are many colision in Registraiton Contention
Slots and it is not efficient. How long are Registration Contention
slots?
Second, in Figure 49--Example of burst FDD bandwidth
allocation, it's not follow the rule that is described in 2.6.4 PHY burst mode
support(Page 114). In 2.6.4, TDM portion is used by full-duplex SSs and
half-duplex SSs that are scheduled to transmit later. And TDMA portion is used
by half-duplex SSs that are scheduled to receive later. In Figure 49, there is
gap in down stream between blue and green(1'st frame), between red and blue(2'nd
frame). I think these gaps are transition gap between TDM and TDMA.... But I
can't explain 3'rd frame.... There is no gap in 3'rd frame's DOWNSTREAM... But
following 2.6.4, there must be gap between blue and green in 3'rd frame's
DOWNSTREAM. So I think 'The gap is for Tx/Rx transition of half-duplex SSs. Then
how can allocated slot? It's too complex.'. It's right? What is the mean of gap
in each of the frame?
Thank you for reading this mail. And I am sorry
about my poor English. Please reply to this mail.
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