Subject: [16NG] IEEE 802.16 QoS parameters

From: "Denio Mariz" <[email-masked]>
Date: Tue, 5 Jun 2007 15:03:37 -0400

Hi,

IEEE 802.16-2004 document defines some QoS parameters for admitted
connections, which includes maximum latency and maximum jitter. They
are defined as:

=======
Maximum latency - The value of this parameter specifies the maximum
latency between the reception of a packet by the BS or SS on its
network interface and the forwarding of the packet to its RF
Interface.

Maximum Jitter - This parameter defines the maximum delay variation
(jitter) for the connection.
======

Assuming D1 and D2 as the delay measured for two consecutive packets,
it is common for end-to-end systems to compute the jitter J as
J=|D1-D2|.

I am studying a scheduling algorithms for the download, which must run
inside the BS. This means that D1 and D2 are not available (or must be
avoided, since it would depend on measuring them at the mobile
terminal). So I am assuming that the algorithm must only consider
information from inside the BS (more specifically from queue
statistics).

So, I am wondering if it is possible to compute correctly the jitter
for packets assuming you can not watch the receiving end of the stream
and only consider info from the sender side.

TIA,

Denio Mariz

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---

From: "Denio Mariz" <[email-masked]>
Date: Tue, 5 Jun 2007 15:01:33 -0400

Hi,

=======

TIA,

Denio Mariz

---

From: <[email-masked]>
Date: Thu, 21 Jun 2007 18:19:35 +0530

Hi,

Provision for maintaining the Jitter lies with the receiver of the
packets and only if
some feedback mechanism is there, receiver can inform the sender about
the jitter.

At the sender's end it may not be possible to calculate jitter(even
based on queue stats), 
as even if packet has gone out of the sender's queue, does not guarantee
it reaching the receiver's side. 
At the receiver, it can be that Packet might not have reached or reached
but dropped due to jitter threshold 
being reached/jitter buffer being full.

I think all sender can do is to pump out data at a regular rate over
time at which receiver is able to receive 
and rest lies with the receiver.

regards,
Keshav

-----Original Message-----
From: Denio Mariz [mailto:[email-masked]] 
Sent: Wednesday, June 06, 2007 12:32 AM
To: [email-masked]
Subject: [16NG] IEEE 802.16 QoS parameters

Hi,

IEEE 802.16-2004 document defines some QoS parameters for admitted
connections, which includes maximum latency and maximum jitter. They are
defined as:

=======
Maximum latency - The value of this parameter specifies the maximum
latency between the reception of a packet by the BS or SS on its network
interface and the forwarding of the packet to its RF Interface.

Assuming D1 and D2 as the delay measured for two consecutive packets, it
is common for end-to-end systems to compute the jitter J as J=|D1-D2|.

So, I am wondering if it is possible to compute correctly the jitter for
packets assuming you can not watch the receiving end of the stream and
only consider info from the sender side.

TIA,

Denio Mariz