How far to re-use Scrambling Code?

For 3G live Network. Please check

1. According to your scanner tool result.Same SC within same area are prohibit.
2. Check in neightbor list.No same SC in each NB list.

Did you agree with me?

UE Sensitivity VS HSDPA Throughput

Today,I perform 3G in building walk test for HSDPA.I found that UE sensitivity is an another major factor of HSDPA speed. Less UE sensitivity will make low T/P.

I think that CQI effected by UE sensitivity.

Low sensitivity --> Low RSCP --> Low Ec/Io --> Low CQI --> And low HSDPA T/P
More sensitivity --> High RSCP --> High Ec/Io --> High CQI --> And absolutely High HSDPA T/P

HSDPA Miss Understood

On last workday I found miss understood with my colleague,he say he want to make HSDPA network with guarantee bit-rate all of certain area, So poor man I said to him "Did you known HSDPA throughput are Best Effort"

You can't guarantee HSDPA bit-rate,Actually its depend on CQI (Channel Quality Indicator) but finally its depend on number of user among that cell.Throughput are very on CQI and number of user time by time.

Almost all of telecommunication engineer who was work with 2G system alway confuse with this topic.

:Mark my word pal, "HSDPA T/P are Best Effort"

RRM Admission Control

Admission control decides whether or not an incoming call can be accepted. A new radio connection is admitted by the CRNC which accounts for the available resources at the corresponding Node B. The allocation of resources includes the allocation of the corresponding downlink spreading and channelization code pair. The objective of admission control is to maintain call quality in each cell by limiting admission of radio bearers. If radio bearers were granted without limit, the interference level in the cell would increase, leading to degradation of the call quality. In addition to the admission control function in the RNC, the Node B performs admission control to protect the Node B against too high transmission power requirements. The Node B estimates the transmission power requirement of a new radio link and verifies whether the total transmission power is below the maximum allowable transmission power.

Feature comparison between R99 and HSDPA

Above is feature comparison of HSDPA and R99.For my opinion the big change are Modulation Scheme, TTI and Soft Handover Type.

Let talk about Handover, for HSDPA only one active set can be clamp in one time. Modulation scheme very due to air condition time by time (Ec/Io) and Transmission Block reduced to 2 ms.

What is UMTS RRM Function ?

The function for managing radio interface resources of the UMTS Terrestrial Radio Access Network (UTRAN) are called Radio Resource Management (RRM) function. The RRM functions aim to ensure the optimum coverage and high call quality as well as to maximise the system performance through efficient use of radio resource.

You can down load All 3GPP DOC. from 3GPP FTP Link

Multi carriers dedicated for HSDPA and R99

The advantage of this carrier strategy is the performance improvement of both HSDPA and R99 calls. Since the separated carriers are prepared for each technology, the possible interference between R99 and HSDPA would be minimized. In this configuration, the code allocation problem shown in single carrier strategy can be also avoided. The disadvantage of this configuration is an impact on the investment and running cost since this configuration will require high power amplifier for multi carrier operation and other necessary resources such as Iub and base-band resources which is necessary to be prepared for each cell (e.g. common channels). In some case, the licensing scheme contracted between operator and vendor may be also related. If cell license is applied in the contracted license scheme, the increase of the number of cells will affect on the amount of license fee to be paid.Another concern of this cell configuration strategy is the mobility of HSDPA call. The following figure illustrates the case that the area where single carrier strategy is applied is adjacent to the area where multi carrier is applied. Fig. below HSDPA mobility problem In this case, when HSDPA user is going to move from single carrier area to multi carrier area, HSDPA user prefers to be handed over to the HSDPA cell for HSDPA service continuity.

In this case, when HSDPA user is going to move from single carrier area to multi carrier area, HSDPA user prefers to be handed over to the HSDPA cell for HSDPA service continuity.

However it depends on the supported functionality of the equipment vendor and also depends on the specification of the terminal, even if vendor would like to choose this mobility scenario. In addition, there would be the interruption time during inter frequency handover process in this scenario and such interruption time may worse the end-user experience. Thus the parameters tuning shall be done to minimize the interruption time as much as possible.