WCDMA second carrier, when is needed?

[Tomas Delgado]

Hello, when is a good time to deploy second carrier in WCDMA. Is there some document supporting the theory about when is the right time to deploy?

[coursekec]

To my knowledge, I think when capacity needs to be increased another carrier is added along with an additional baseband processing card...

[wolverine]

When you start getting RRC and RAB rejects due to lack of power and codes is a good starting point. Also when your HS performance suffers because of R99 traffic (which takes priority) you can deploy a second carrier and keep your HS traffic separate.

[riverstreamer]

As "wolverine" explained you can find the time in this away.
In addition in first days you have dimensionned your network over some targets in Capacity-Quality criterias. check these criterias in your live network; like the items that our friend explained. It shows you that you need another carrier or not. Generally Traffic over HSPA connections are much important and after it over R99. This points can impacts your access network throughput and your access network connection qality.

[Tomas Delgado]

Ok, some document for it please ? and how to evaluate it when the network is running? ... I usually add a 4th or 5th cell in a site that has power or code congestion and it works fine. Also i can add a new site near the area to take traffic form that cell or site and also works fine. But i think i cannot put more sites near this place, i mean till what point i can make this type of expansions, there must be some criteria telling you ok this area you can not put another site nor adding cells to the site it must need another carrier.

[yoronjo]

Ok, some document for it please ? and how to evaluate it when the network is running? ... I usually add a 4th or 5th cell in a site that has power or code congestion and it works fine. Also i can add a new site near the area to take traffic form that cell or site and also works fine. But i think i cannot put more sites near this place, i mean till what point i can make this type of expansions, there must be some criteria telling you ok this area you can not put another site nor adding cells to the site it must need another carrier.

when RTWP reaches the threshold (for Huawei the more you reach -85 dBm RTWP, the more you need to deploy the second carrier),
when total cell power utilization has increased (i think this one is at 48%),

you can add another carrier as early as possible and do some inter carrier load sharing in order to give your subs high throughput as well (since cell throughput is shared among subs)

coursekec is right, increasing your carriers increases your subscriber capacity as well, so just be on the lookout regarding your node b's CE utilization. :)

don't have my working terminal with me. i'll upload Huawei's guidelines for 2nd carrier expansion later.

regards :D

[redernesto]

here link about second carrier
http://www.finetopix.com/showthread.php?t=12416&highlight=huawei

[yoronjo]

here link about second carrier
http://www.finetopix.com/showthread.php?t=12416&highlight=huawei

thanks redernesto, here is another file that might also help @TomasDelgado

http://www.finetopix.com/showthread.php?p=100353#post100353

[sekit]

Maybe this can help you! :)

[salamanda1969]

In our network, weekly stats are collected to identify cells that have broken critical KPI. To trigger 2nd carrier, the data-related critical KPI have to be broken consecutively for 4 weeks or more. KPI triggers include CE utilization (max CE installed), UL noise rise, simultaneous HSDPA users, DL power, etc. When marketing is planning to launch cheap data package/plan, it's also time to install F2. Hope that helps.

[driss240]

I couldn't download it when
thank you for pass me this document on this email dr.tahiri11@gmail.com (http://www.finetopix.com/dr.tahiri11@gmail.com)

[mobilink999]

You will need second frequency for expansion. Also you can have strategy to have once freq for voice and one for data.

[sharyfor2]

In our network, weekly stats are collected to identify cells that have broken critical KPI. To trigger 2nd carrier, the data-related critical KPI have to be broken consecutively for 4 weeks or more. KPI triggers include CE utilization (max CE installed), UL noise rise, simultaneous HSDPA users, DL power, etc. When marketing is planning to launch cheap data package/plan, it's also time to install F2. Hope that helps.

I agree that 2nd carrier help in increasing capacity, but what if your site is still using the old number of E1's. I mean if a 3G site ABC is linked by 5 E1's before expansion i-e before addition of 2nd carrier and after the expansion its E1's amount remain the same, then how your expansion benefited the high number of PS user around that site.

[agenov]

I agree that 2nd carrier help in increasing capacity, but what if your site is still using the old number of E1's. I mean if a 3G site ABC is linked by 5 E1's before expansion i-e before addition of 2nd carrier and after the expansion its E1's amount remain the same, then how your expansion benefited the high number of PS user around that site.

In the meaning of resources the main driver for second carrier introducing is lack of DL codes, also can be added in specific cases and UL/DL power as other resources at cell level. For those related to NodeB like CEs and Iub second carrier can not benefit of course.

BR
Alex

[driss240]

salam Brothers and Sisters,

maybe this file can help you

Introduction to additional WCDMA carriers.pdf - 4shared.com - document sharing - download (http://www.4shared.com/document/Eh88ywYD/Introduction_to_additional_WCD.html)

[venom]

Hello, when is a good time to deploy second carrier in WCDMA. Is there some document supporting the theory about when is the right time to deploy?

Simple Answer --> To overcome Air Interface Congestion

[ercanaktas]

sekit hi how can ı open your doc

[Saadiyad]

when you will reaching the maximum throuput and you need to serve more for the customer with loadsharing activated

[sekit]

Use my default pass to open rar files

[maq17]

It is a bit difficult planning second carrier deployment. Some RF Planners only consider PS Traffic (6Mbps) or CS traffic but it isn't enough.

For preventive practice you can analize downlink average power for R99, a good threshold value could be 40dBm; also check uplink interference : If you use NSN you can see PRx Noise, so you can calculate the difference, remember that 3G systems don´t work more than 30dB over noise in uplink, so 15dB could be a good threshold value. Code congestion is also a KPI to analize but I didn't get a correlation with average code tree usage vs code congestion so I dicarded it. Check HSPA users too, remember that for example in NSN the limit is 64 users per cell.

For corrective situations you can check KPI's related to admission control due to lack of codes or overload in downlink power or excessive uplink interference. That could be experienced as an access failure for a normal user

If you have problems with spectrum or with a few sectors, you can increase the number of sectors without increasing carrier. Normally we use 65 degrees antennas with 3 sectors, so you can increase up to 6 sectors per site with 33 degrees antennas

[rffreeconsult]

From the operator viewpoint, they will calculate the number of cells that are downlink-power congested for more than 3 weeks consecutively, and the number of cells that are DL-code congested for more than 3 weeks with a certain threshold ( for ex: 75% power congestion and 80% DL code congestion). The combination of these 2 lists will produce the candidate lists for additional carrier (2nd or 3rd or 4th). This site list can be cross-correlated with Top Access failure list for further isolating those cells that are highly congested that it has high-access failure (CS and PS/HSPA). The 2 afore-mentioned lists can be used either separately or in combination for finalizing the additional carrier list. Please note that all optimization efforts should have been exhausted before considering the sites for additional carrier as it carries a certain costs. The 2 carrier repartition are as followed: 1 on voice and 1 on preference for data (especially HSPA) by default parameter config setup.

[lihanbok]

You want to have WCDMA second carrier when you want increase your capacity and reduce interference. In the crowded area,if you use many sector may be high interference. when you use R99 and HSPDA together, R99 is affected. They usually use 1 carrier for R99 and HSPDA, 1 carrier for HSDPA in the high capacity.

[darshanmalde]

for mentioned kpi in previous threads one can also add new site for example in case of code utilization. my query is how to quantify when will you require 2nd carrier and new site?