VzW is intensifying its deployment of C-RAN in an attempt to try and solve in-building coverage gaps in dense urban environments. Inadvertently creating serious Radio Access Network (RAN) QoS problems due to the high RAN latency C-RAN architectures.
Delayed modulation decision making and high latency issues in the "cloud e-nodeB pool model" will definitely impair streaming services, eg, VoLTE, VTC, VoIP, Movies, online radio and any other timing sensitive applications. Forward error correction (FEC) overheads and poor RF conditions will exasperate the problem, and the outcome will be more to deploy more DAS and small cells.. 3GPP optimized LTE RAN latency to 5.5ms by moving the radio network controller (RNC) and radio resource controller (RRC) from the core network to the e-nodeB., C-RAN architecture creates serious latency hazards and bottlenecks that will need to be considered, it's architecture is inherently not optimized for LTE latency and this blogger still believes DAS and small cells are superior for LTE and 802.11x WiFi deployment.
If you want a quality in building and campus wireless experience contact Fast DAS. I'm in the midst of writing a research article about C-RAN now. If you like, I will send you a link when it’s ready just shoot me an email at email@example.com.
Blogging again after such a long hiatus brings that tune "its been a long time, since I left you without a dope beat to step to" to mind. Its been so long I'm probably blogging to myself I dunno. Is anyone out there? We're gonna find out... so, please leave me a comment so that I know I'm not just talking to myself. lol, seriously lets get back on topic.
Okay space cadets, if you haven't already read and commented on my articles please check them out by clicking on the picture below! Leave me a thoughtful comment and you will get a lollipop.
5 fundamental parts of network implementation
Networks move toward all LTE and Wi-Fi Models
Q&A: The Operator Owned Neutral Host DAS
Top 3 Ownership Models for Neutral Host Distributed Antenna Systems
Signal to Interference Noise Ratio or SINR is the most important factor in determining the capacity of an LTE channel in the Air Interface. Fact: Bits/Hz = Bits/$$ A poorly designed system can't compensate for the losses.
Bits/Hz = Bits/$$ and this is a fact. If you've paid for the spectrum license, invested in the infrastructure, built out the network all with a focus on your spectrum strategy, then you really need to pay attention to this fact. Don’t lose customers because you partnered with a general mills IT company.
Fast DAS, LLC is a one stop, DAS shop. We respect your investment in mobility and we are experts in building RF engineering solutions. To optimize SINR requires looking at a lot of different power metrics and physical installation inspection. How you lay out your system makes a difference and so do the individual components in your system. We can isolate problems, trouble shoot your system, bring your network up fast, and help you monitor and maintain it too.
Fast DAS has scaled the NMS endeavor so its easy for us to maintain and operate a virtual NOC.
If it has this seal on it, it's a Fast DAS!
There are so many topics to cover when we consider Multiple Input Multiple Output (MIMO) that we will have to narrow the focus to get anywhere. MIMO requires good diversity! How much depends on the frequency and distance from the transmission. There are ways to improve diversity and it has to do with Phase shift. LTE is a robust broadband with excellent forward error correction (FEC) built in. It also has the added feature of scheduling energy only into the Resource Blocks (RB) that are in the best RF conditions. I know it sounds scifi, but I've seen this phenomenon while testing on Ericsson's eNode B in Sprints Lab. The LTE Channel energizes consistently on the RBs that have the best SINR. This is easily provable with the right test setup.
Depending on many factors including physical distance, Tx power and Rx Sensitivity RF transmissions are either 64-QAM capable or they are not. MCS is mapped to TBS in 3GPP standards so we can easily see that SINR is far more important than RSRP specifically when it comes to capacity in the air interface.
There are cost of ownership considerations when planning how one will zone and sectorize a DAS in the future. Depending on how you lay out zones you can gain or lose flexibility in future upgrades. Zoning must consider future upgrades and be scalable to meet the capacity demands of the future with minimal reconfiguration costs.
We are big advocates of all fiber architectures. They reduce passive intermodulation (PIM), increase link budgets, and virtually eliminate signal single points of failure like coax, circulators, combiners and splitters. du-,di-, & multi-plexers are types of combiners. Couplers are lumped with splitters because they are unequal power splitters. These architectures are cost effective and performance tuned. You can even ride Wi-Fi and Public Safety Radio (LMR) or Land Mobile Radio along with any other mix and match of frequencies and technology channels. Link budgets are intended to control power, not blow it away. A macro can do that with a single sector. But if you are deploying at a high capacity venue with one sector, its only workable if you are gaining capacity in the air interface via spectrum vs sectorization.
All Fibers are immediately field OTDR tested to within 5% of their cut sheet specification.
Can QoS be sustained in the www? With buffers? Forward Error Correction (FEC) built into the standards? Whats the overhead of various SON features you're considering? Have you thought about what it takes in capacity and hardware/software processing power to make modulation decisions every 1 ms (TTI)? Welcome to LTE Testing 101. Three dimensional measurements tell the whole story in time, frequency amplitude, all based on modulation scheme.
We are moving towards all LTE models, mainly because it is the most spectral efficient technology. Its capabilities to carry bits/hz has everything to do with its modulation which has FEC built in. There are SON and ICIC features that build on this concept and We believe IMS will grow to take it to the next level. What are your thoughts?=)
We certify results with calibrated measurements in raw format as well as data tables. You can't fake this stuff. How do you like your RF data formatted?
Simulate and test for RF performance for EVM and ACLR with the Bugatti of LTE Signal Sources. Rohde and Schwarz claims...."Easy signal generation for digital standards such as LTE and LTE-Advanced using the R&S®WinIQSIM2™ simulation software."
This has MIMO, KPI Optimization, Capacity and load balancing design implications folks. Hopefully you won't miss the webinar!
As I write this post, AT&T is in the midst of a major small cell deployment initiative. The lessons learned from the cost vs benefits of gaining capacity and coverage in this way are of great anticipation to all of us in the wireless industry. It is yet to be seen if this model will become the standard but we suspect without a fiber DAS the costs will be prohibitive especially in very large high capacity venues. What are your thoughts? Concerns??
This is where you can get answers to your toughest technical questions. Use our community of experts to test your theories and get advice from those who have been there and done that. =)
The goal is to make a lot of friends while asking questions and sharing information not misinformation. We respect all thought and points of view, we recommend sticking to RF theory, Standards and what’s provable by math, and require 99.9% civil conduct and proper manners at ALL times, because nobody is 100% right or perfect.
No other rules for now.
Farzin S. Yazdani
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Veteran Owned Small Business,
2112 Statute Lane,
Vienna, VA, 22181