Scheduler is used to assign resource blocks (RBs) to all the users according to the traffic demand.
Does all the RBs assigned at all TTI's or the number of RB depends on traffic and varies with each TTI?
If it depends on traffic, then how should I decide RB assignment per user?
Dear,
if we have BW 10 MHz then total RBs are 50, these 50 resources available every TTI (1 ms), the 50 resource blocks are available every millisecond. If the eNB has data for 100 UEs, then it will take at least 2 ms to serve all of them, since at most 50 can be scheduled in any millisecond.
eNB can serve up to 100 UEs simultaneously in each TTI (assuming 1 RB/UE criteria). Moreover, in actual traffic conditions, all UEs are not always in active state, but quite a few are in Idle state and that also helps eNB to manage active UEs efficiently.
Thank you khalid.
But my concern is that in a conventional network whether all the RBs are allocated at every TTI's irrespective of the number of users present. For example if I have a total of 50 RBs, then if I have now a single user, should I allocate all the RB to that user or not?
If this is the general case then at every TTI, I would have to allocate all the available RBs irrespective of the number of users. But in practice I have read many literature's where it is mentioned that a single eNB will experience different traffics at different times of a day. Full traffic means all the RBs are used whereas 50% traffic means half of the total available RBs are in use.
Now if I use a specific traffic model, then depending upon the available traffic, how should I decide how many RBs to be used?
Dear,
As you know, Every ms (subframe), the RBs are allocated to one or more of the active users; two users will not use the same RBs in that subframe. In the next subframe, all of the RBs are reallocated to the users as needed; there is no guarantee that the user will receive the same RBs as before (or even any blocks at all).
Hi Abdullah,
You have to know speed of processor/processors/network/memory/resource generaly. you also have to know what is time of single thread in stack so you can divide speed with time in stack. that number is youre RBs. Time spent in stack depends on nature of youre job needed to be done, time waiting, thread priority and job complexity.
PS: beware of "dead locks" or "trafick lock".
Following papers will also help your understanding regarding this topic:
A.B.Shams, S.R.Abied, and M.A. Hoque, "Impact of User Mobility on the Performance of Downlink Resource Scheduling in Heterogeneous LTE Cellular Networks." 3rd International Conference on Electrical Engineering and Information & Communication Technology (iCEEiCT), Dhaka, 22-24 September 2016.
Link: Conference Paper Impact of User Mobility on the Performance of Downlink Resou...
A. B. Shams, S. R. Abied, and M. F. Hossain, "Performance comparison of network layouts with mobile users under different resource scheduling techniques in downlink LTE." 5th International Conference on Informatics, Electronics and Vision (ICIEV), 2016.
Link: Conference Paper Performance Comparison of Network Layouts with Mobile Users ...
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