U.S. Patent No. 6,640,248 is directed to bandwidth allocation by type of software application. The specification describes the allocator as being at the data link layer of the OSI standard and using information from the application layer, transport layer, or network layers of the OSI standard (pages 2-4). The claims recite an “application-aware media access control (MAC) layer” and an “application-aware resource allocator” (page 5). The dispute is over whether information acquired from the application layer is required (page 5). The ordinary meaning supports use of the type of application from any of the application, transport, or network layers as the claim limitations merely require awareness, not how the allocator becomes aware (pages 7-8). The specification and claim differentiation support this breadth (pages 8-9). The prosecution history statements that application aware refers to information from the application layer refer to awareness of the application at that layer, not how the awareness information is obtained (pages 10-14).
Hindsight: In prosecution, it may be best to keep in mind the alternatives and make the arguments generic to the alternatives. Being precise in language may help as well, such as focusing on the awareness and not how made aware as was done in this case. Alternatives in the specification helped in this case.