RC4 in CDMA2000 1x SCH

[hamody2005]

Hi

Does any one know what's the disadvantage of enabling RC4 (or ARC) for SCH only in CDMA2000 1X network?

[live4case]

I think the disadvantage of enabling RC4 (or ARC) for SCH is consume to much power and let the neighbor sites have same function during handoff only
also there are three condition to control this function 1 power 2 walsh 3

[T_ADD]

Activating RC4 instead of RC3 has some advantages. But like with any tuning, there are trade-offs. RC4 can greatly increase 1x capacity for both voice and data at the expense of dropping the Tx power a little bit because in RC4 the modulation data rate changes from 9.6kbps to one step up (can't remember the exact value). Using RC4 is handy when you have TCH congestion issues but don't want to add extra channel boards (CCPM cards). It's most practical to use RC4 for urban/dense urban sites with 1x data where your coverage area is within 30-40 kms. If used in cells with higher coverage radius, there's risk of TCH failure due to forward power loss. In other words, you'll need to check this stat in M2000 once you activate RC4. Also with RC4 the walsh code base rate changes from 64 to 128 and hence the capacity increase.

In my network, I've activated RC3 for voice (because for voice RC3 is enough and TCH congestion is more from data than voice, so RC4 not really needed and is handset dependent) and RC4 activated for data in urban sites. The threshold percentage is set to 50%. After this config, I had no issues with TCH congestion.

ARC means automatic RC3 or RC4 assign depending on air link assessment. You can use ARC if a cell serves subscribers that are near and far as well. That way the one near by will be assigned RC4 and the ones far out RC3.

If you want to know your cell coverage range from M2000, check the traffic modeling stats. Its all there.
Hi

Does any one know what's the disadvantage of enabling RC4 (or ARC) for SCH only in CDMA2000 1X network?

Sent from my ADR6300 using Tapatalk 2

[T_ADD]

Found the doc while going through my archive.

[hamody2005]

Hi Mr. T_ADD

I've read your DOC But I have some questions?

1. Why CE usage In RC4 is half of RC3?

2.Does the new Qualacomm CSM chip use the same relation of CE usage in SCH?

Because I have heard the New CSM chip can process all rates by one CE.

[T_ADD]

Hi Mr. T_ADD

I've read your DOC But I have some questions?

1. Why CE usage In RC4 is half of RC3?

2.Does the new Qualacomm CSM chip use the same relation of CE usage in SCH?

Because I have heard the New CSM chip can process all rates by one CE.

Hi hamody,

1. That's because the Walsh code space is increased from 64 to 128 (doubled).

2. The CE usage part is according to RC, not the CSM version. But newer CSM cards just have more CEs for capacity and support 3 - 6 more carriers rather than just 3. Newest one I think is CSM6700. You can check the specs sheet from Google.

Sent from my ADR6300