I don't want to open a "can of worms" but I have some remarks regarding the philosophy behind Dr. Costa's submitted document.
(1) Cable modem technology for wireless seems like a great short cut. Yes - it is possible to hook up a up/down RF converter and an antenna and "BOOM..." we go wireless. However the true question is not if one can use such a technology to demonstrate the wireless concept. The true question is if this technology is suitable for commercial deployments of BWA, meaning achieving required coverage and service level (i.e., capacity) and at the right price.
(2) A few meetings ago John (from SiCom) presented a paper which points out some issues associated with wireless which are not addressed by cable modem. I do not want to go over all the issues but one major example is RF planning (re-use) which is not an issue for cable but is a "biggy" for wireless. For example, a service provider would be surprised to see that he does not meet his high capacity deployment targets even if he splits each "cell" into a large number of sectors (8,16...), and was using QAM-256/64 modems with aggressive re-use plans.
(3) Let us not forget about the word "Access" in BWA. Cable modem technology evolved around video and internet to the home. Our target is broader and therefore I would question if cable modem MAC technology is suitable.
(4) There is another example from the past which is very relevant. During the days before 802.11, people actually thought that they could take 10BT (Ethernet) and transmit /receive it by wireless means. This almost worked until the whole concept of "Carrier Sense" had to be re-investigated due to near-far problems (i.e., a user could not sense another user using a radio channel directly because he was too far). Let us learn from this example.
Cable modem technology solves sophisticated problems. However most of these problems are not relevant to wireless. Other issues which are specific to broadband wireless access are not addressed at all.
Bottom line - BWA is not about technology shortcuts. This does not mean that we have to re-invent the wheel. There is a huge knowledge base out there and it has its roots in wireless, such as PCS/Cellular, WLANs etc.
From: Roger B. Marks [mailto:firstname.lastname@example.org]
Sent: Wednesday, May 05, 1999 6:32 AM
Subject: stds-802-16: updated Liaison report from ITU-R 8A/9B
[Notice: It is the policy of 802.16 to treat messages posted here as non-confidential.]
Dr. Costa notes that the word "PRELIMINARY" should have been removed from the
"DRAFT NEW RECOMMENDATION ITU-R F.BWA: RADIO TRANSMISSION SYSTEMS FOR FIXED
BROADBAND WIRELESS ACCESS (BWA) BASED ON CABLE MODEM STANDARD". I have
posted the updated version he provided.