Hi folks, I'm having an interesting dialogue about the subject topic offline. One of our engineers embedded in one of the largest BWA networks in North America (450+ base stations/over 70k CPE) has chimed in. His comments bear spreading to the community. The responding engineer cut his teeth years ago working for a major mobile carrier. The trigger for the discussion was an assumption that re-use of 1 is a viable choice for fixed networks today.
Reuse 1 is being used widely in mobile as users (omni antenna) are typically not guaranteed any throughput per their fixed location meaning center of sector great throughput but cell edge very poor. In broadband wireless and all the testing of Reuse 1 I have witnessed there is significant degradation to users on the cell edge. This means the only business model that can work with reuse 1 in its current state would be the mobile strategy which is no committed rate and users don't sit around executing speed tests to audit their providers service. The LTE concept of equal time means that the only time a cell edge user could get any throughput is when there are no active users in the cell center . One of the main issues with Reuse 1 today is that is implements static ICIC which is actually no better than WiMAX reuse 1 aka FFR0. FFR 0 statically divided the map zone(control plane) into 1/3 and allocated a different 1/3 of the bandwidth to each sector. This is essentially the same thing that is done with static ICIC in LTE and we know it does not work well in either technology i.e. WiMAX or LTE There are advances planned that will improve this situation, but all of which are still in the works. Adaptive ICIC- unlike static you are not limiting your cell edge to only 1/3 the bandwidth constantly. In this scenario the eNB is allocating a reuse pattern on a dynamic basic using any of the following reuse 1, reuse 3, reuse 6. This of course is still only frequency based scheduling as freq and power are coordinated eICIC - eICIC not only schedules freq and power in coordination it adjacent cells, it also coordinates time by implementing the ABS (almost blank subframe). With eICIC or any other interference coordination schema there is still the trade off of resources as sectors and adjacent eNB coordinate the sharing of the same freq and time resources. CoMP - Coordinated Multipoint which is a much more advanced feature set that allows for the joint scheduling of a single UE from multiple eNB. The benefit here is the receiver gain on the downlink along with the leveraging of a interferer signal to be utilized as a usable signal in combination with the primary serving eNB. On the uplink it's the same concept as multiple eNB receive the UE transmission and combine it forming a virtual array. +++++++ If you have questions or comments, I can forward them to the engineer for further elaboration. Cheers, Patrick Leary M 727.501.3735 [cid:image003.png@01CF4357.3B1EE550]<http://mkt2.us/TelrdNet> ************************************************************************************ This footnote confirms that this email message has been scanned by PineApp Mail-SeCure for the presence of malicious code, vandals & computer viruses. ************************************************************************************
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