Wi-Fi Design Strategies in a Converged World Webinar Questions Part 2: Convergence
Events (September 01, 2017)

Wi-Fi Design Strategies in a Converged World Webinar Questions Part 2: Convergence

We are a few days late in posting our second installment but here it is. This week's topic is convergence. Our attendees had a lot of great questions about this topic and here are the answers by our experts. 

And in case you missed this webinar or simply need a refresher, here is a link to the recording: Wi-Fi Design Strategies Webinar.

Oh and we also have a 15-day free trial of iBwave Wi-Fi, so give it a try!


1- Is this the future for DAS deployment?

[Ronald] No it is not, both DAS and Wi-Fi networks will exist next to each other as covered in the presentation. Note that iBwave has products for both DAS and Wi-Fi as wireless architects need these tools to do the RF-planning


2- Wi-Fi vs DAS designs. How do you design for both in 1 DAS?

[Ronald] As covered in the presentation there are different type of DAS solutions (passive, active and hybrid), Wi-Fi on a passive DAS does not work so well. Active DAS with PoE (Power over Ethernet) components to power up Wi-Fi APs could be a solution to use the DAS cabling purely for the backhaul traffic. Note that iBwave has products for both DAS and Wi-Fi as wireless architects need these tools to do the RF-planning.


3- Historically Wi-Fi & Cellular DAS systems have not worked well on the same infrastructure.  What is different now?

[Ronald] Correct, the reason is “Hidden Node” the Wi-Fi protocol does not work well over DAS. We discussed co-existence in the buildings, but also some vendors use integration whereby DAS is used as backbone (“active DAS” with PoE ethernet adapters, but still using the normal Wi-Fi APs)


4- Comparison between indoor DAS, Wi-Fi. Based on which criteria to choose them?

[Ronald] They co-exist and will not replace each other.


5- Do you have more information on remote Wi-Fi APs (connection through DAS)?


6-What is the summary of a step-by-step approach for engineering a balanced Wi-Fi, Small Cell and DAS converged environment?

[Ronald] This approach is in progress for Wi-Fi by the WLAN Association (WLA), see the link in the webinar presentation, but in general the approach works for any wireless network.

  • Get the requirements (end-users, # devices, roaming, costs, etc.) “Red book”
  • Design the network “Blue book”
  • Install “White book”
  • Validate “Green book”

And in addition, there should be also one covering

  • Operate and Monitor


7-Do you have some of the best/new design tips or products being used in design for "CONVERGED NETWORKS" In-Building?

[Ronald] Design Tips: Separate the Wi-Fi network from the DAS network (and at airports maybe have 2x DAS networks as mentioned, 1x for public safety services (like the first responders, police, etc.). Roaming/convergence services for Wi-Fi and LTE/5G also depends on the client device capability (e.g. software to determine which network provides better services and throughput)

Products: iBwave Enterprise (as it integrates the different networks, like Cellular/Mobile, DAS, Wi-Fi, etc.  (different Frequency ranges)


8- Future of in-building wireless phones Voice over LTE (VOLTE), Voice over Wi-Fi, others.

[Ronald]Correct. You typically design per floor level to have good RF coverage and Capacity for clients for different areas. If you have open spaces (like Atriums, you need to take that into account, maybe AP Transmit Radio Powers need to be reduced to avoid RF leakage through those Atriums, which means that suddenly clients see too many APs)

In the design tool (between the floors) you also need to see the attenuation levels (e.g. a very thick concrete floor or not), but if the APs can hear each other in 3D, then you also need to look at the Channel allocation that they do not interfere on the same channels (e.g. APs “stacked” on Channel 1).


9- Wi-Fi in trains(wagons) using external 3G/4G networks

[Ronald] 3G/4G need to be used as the backhaul and there need to be enough capacity to handle the Wi-Fi traffic (e.g. downloading videos, doing voice over Wi-Fi calls and doing performance tests might be prohibited). Other aspects to take into account are Wi-Fi Mesh connections between the wagons (as wagon configuration sometimes changes it is difficult to lay cables between the wagons). Also note that other type of services can run over the Wi-Fi network (e.g. CCTV or IPTV camera monitoring). There are many examples of Wi-Fi in train projects if you search in twitter on hashtag: “#WiFiTrains”


10- Do we need to increase the unlicensed spectrum allocation for LTE and Wi-Fi for a better mobile offload strategy?

[Ronald] This is not so easy to do (see for example the US Spectrum Allocation Chart link) as most frequencies are used already. It is a difficult topic where also the ITU-R plays a part in it to coordinate with the different countries.


11- Are you designing for generic Cat6 or Belden Cat6

[Ronald] The presentation has a vendor neutral approach (with a link to iBwave Wi-Fi design how the tool can help design Wi-Fi / cabling also from a vendor neutral approach). The focus was on the Wi-Fi design, but we covered also cabling design and standards (like 2.5 GBps and 5 GBps over Cat 6 cabling and PoE++ requirements). Also, the webinar presentation has a link to the BICSI Winter conference presentation - who is designing your network (the cabling or the Wi-Fi expert)? (Ref: https://www.bicsi.org/uploadedfiles/bicsi_conferences/winter/2017/presentations/CONCSES_2E.pdf)


12- I would like to know about the impact cabling has on Wi-Fi networks planning

[Ronald] This was covered in the webinar, like type of speed needed 2.5 Gb/s (Cat 5e cabling) or 5 Gb/s (Cat 6 cabling), length limitations and also PoE (Power over Ethernet considerations to power up the APs). Then the cabling architecture deployment (TIA TSB 162 and/or the Zone based cabling architecture (see the Siemon document).  But a separate Wi-Fi architecture need to be done for the “last link” cable to be laid from the Telecom Outlet / Service Outlet to the AP.
(do not deploy APs following the Telecom Outlets or all in a line, APs need to be placed were needed for RF coverage and RF Capacity)


13- The cable limitation of 100 meters how practical is it? What happens if the distance to the access point needs to be farther away?

[Ronald] It is a limitation for the Cat 5e/6 cabling and even to get the higher speeds, the length might be even shorter to provide the good quality signal on the cable. For longer distances (e.g. airport concourse areas) typically the Power of Ethernet switches can have a Fiber optic adapter for the long-distance cables back to the DataCenters, thus only the last mile is copper/Ethernet cabling. You create kind of Telecom-closets around the facility (“distribution areas, based on the length of the copper cabling to the APs and other services in the building).See also the BICSI archives as there is tons of information about cabling (and a related certification known as RCDD): https://www.bicsi.org/single.aspx?l=1712

Winter Conference: https://www.bicsi.org/winter/2017/attendee.aspx?id=8734


14- Carrier Off-loading to Wi-Fi.

[Ronald] Carrier off-loading to Wi-Fi (e.g. 3G / 4G offloading) also has to do with the “agent-software” client devices do detect if the carriers Wi-Fi network is available and services are reachable with a good performance to make a decision to switch networks.

Parts catalog includes switches, patch panels, cabling etc.

[Vladan/Ali] IBwave has digital database that has over 25,000 active and passive DAS and Wi-Fi parts that can be used to design any cellular or Wi-Fi inbuilding network


15- DAS vs. iCN network design?

[Ronald] Assumed is that iCN (= in-building Cellular Network)
The focus of the webinar was on the Wi-Fi design and convergence and/or off-loading to cellular/mobile networks. See also the other questions here related to DAS and iCN.
(note: iCN can also refer to Information Centric Networks (ICN)
https://newnet.telecom-paristech.fr/index.php/icn-das/but they refer to DASH (not DAS).


16- Integration with in-building Cellular Network
[Ronald] See the answers to the other DAS and iCN related questions


Next week's topic: iBwave Products,  Stay tuned! 

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