Hi All,
I went through 3 examples of AIF2 in pdk folders, went through AIF2 UG.After that I have few questions on working of AIF2,kindly help me. Taking case of LTE.
1. my goal is to send signal data and Fast C&M. These are to be pushed to two different queues. lets say i pushed Fast C&M first into the CTRL queue [CTRL Channel] of AIF2 and then signal data into DATA queue [one of the DATA channel] of AIF2. now my question is how to ensure that both signal data and Fast C&M are sent synchronously. In other words [though i push Fast C&M (i am pushing 256 control words corresponding to one hyperframe) before signal data], i want to ensure that in every basic frame [within a hyperframe], first word is control and next 15 are signal data, likewise the entire hyperframe should be full without any gaps/holes [in brief,i want to ensure that Fast C&M and signal data is present in entire hyperframe].
CW signal0 signal1 signal2 signal3 signal4 signal5..............signal15 [one basic frame]
2. I have a Vendor Specific info which is just few bytes [16 bytes]. what i understand is in a hyperframe there are 256 control words are possible [i see it on 64x4 matrix on cpri spec] [plz refer CPRI Specification V4.2 (2010-09-29) page 45 --> Figure 15] and within that based on pointer p, there is differentiation [boundary/demarcation] between vendor specific and Fast C&M subchannels. assuming the byte positions in terms of the matrix is
16,17,18,19,80,81,82,83,144,145,146,147,207,208,209,210
[A]. when pushing into Tx CTRL queue of AIF2, should i need to ensure that i form 256 bytes and arrange my Vendor Specific info in following byte positions 16,17,18,19,80,81,82,83,144,145,146,147,207,208,209,210 [note in 256 bytes, 16 bytes are occupied by Vendor Specific info and rest are all zeros] and push into TX Ctrl queue of AIF2.
[B]. if i push just 16 bytes into TX CTRL QUEUE [without forming any 256 bytes], how does the Protocol encoder knows where to place the data. In other words, how to ensure/make sure that the PE puts my 16 bytes of Vendor Specific information in
16,17,18,19,80,81,82,83,144,145,146,147,207,208,209,210 basic frame's control word position [within a given hyperframe].
3. continuing my step 2 question, assume i have both FastC&M and vendor specific info to be sent [according to 64x4 matrix in that CPRI Specification V4.2 (2010-09-29) page 45 --> Figure 15], and each i have just 16 bytes [Fast C&M 16 bytes and vendor specific info is also 16 bytes], assume i push the Fast C&M first and then vendor specific, how does the AIF2 protocol encoder puts Vendor Specific info into appropriate byte positions [16,17,18,19,80,81,82,83,144,145,146,147,207,208,209,210]. and Fast CM into appropriate byte positions [according to CPRI Specification V4.2 (2010-09-29) page 45 --> Figure 15].
4. say, if i dont have any Fast C&M data and Vendor specific data for one subframe [LTE context here], so all along, the data is output to serdes module by AIF2 without any control word. In other words, If i open up hyperlink frame, i should see zeros in all control word positions [of all 256 basic frames], please correct my understanding.
5. Assuming i have data worth of just two hyperframes, and my control word if starting from 200 basic frame within a hyperframe [200th basic frame to 255th basic frame of HYPERFRAME1 and then 0th basic frame to 30the basic frame of HYPERFRAME2], so overall i have (255-200=55) + (30-0=30) = 55+30 = 85 bytes of Control information. On the receive side, how does the descriptor in RxCtrlQ is received [in what size?], do i need to keep data length of 85 bytes in RxCtrlFdq or should i need to stick to 256 bytes of descriptor data buffer size [assuming monolithic] in RxCtrlFdq.
6. say, i sent both FastC&M and Vendor specific information [according to CPRI Specification V4.2 (2010-09-29) page 45 --> Figure 15], how does the other side equipment i.e. RRH will know that Vendor specific information is in first Ctrl word of basic frames [16,17,18,19,80,81,82,83,144,145,146,147,207,208,209,210 basic frame's control word position [within a given hyperframe].]. In other words, RRH has to pick the vendor specific information from these [16,17,18,19,80,81,82,83,144,145,146,147,207,208,209,210] basic frame's control word and Fast C&M from remaining matrix grid [according to CPRI Specification V4.2 (2010-09-29) page 45 --> Figure 15] and how does RRH have knowledge of placement of vendor specific/Fast C&M information
7. In LTE Relay Test Project example, how did you arrive at 704 bytes of Fast C&M information, how to relate it to hyperframe?
Thanks
RC Reddy
