**7. References**


24 Will-be-set-by-IN-TECH

We can obtain mean intensity *M* of overflow stream for various values of *K* as shown in Table 4. The results of calculations show the excellent accuracy of the extended ERT-method. **K M** exact **M** by ERT Rel. error % 0.63322 0.63801 0.756 0.34583 0.34936 1.019 0.17067 0.17128 0.357 0.07616 0.07492 1.634 0.03091 0.02929 5.215

However, such accuracy is not preserved when the number of channels *K* in the final group increases. Table 4 shows values of the loss for different *K* values. It is obvious that for increasing *K* the accuracy drops. For the value *K* = 5 the relative error is greater than 5%. The same effect one observes in Table 1 and Table 2. For decreasing (very small) blocking

There are two parts in this chapter: a theoretical one and an application one. In the theoretical part, we consider four strategies for call admission control (CAC) in single and two-tier cellular networks, which are designed to ensure priority of handover calls, namely: dynamic reservation (cutoff priority scheme), fractional dynamic reservation (fractional guard channel scheme), static reservation (fixed division-based CAC scheme) and restriction on the number of simultaneous new calls admitted (new call bounding scheme). We show the advantage of dynamic reservation by numerical analysis and strictly prove it in the case of two-channel

The application part deals with Equivalent Random Traffic method for multi-tier networks dimensioning. The key result is an extension of the Equivalent Random Traffic method for estimation of the throughput for networks with traffic splitting and correlated streams. The

Aazhang, B. & Cavallaro,J.R. (2001). Multitier Wireless Communications. *Wireless Personal*

Agrawal, P.; Anvekar, D.K. & Naredran, B. (1996). Channel management policies for handovers in cellular networks, *Bell Labs Technical Journals*, 1996, 96–110. Ahmed, M.H. (2005). Call admission control i wireless networks: a comprehensive survey.

excellent accuracy (relative error less than 1%) is illustrated by numerical examples.

*Communications*, Vol. 17 (2001), 323–330.

*IEEE Communications Surveys*, Vol. 7 (2005), 50–69.

Cov

= 1.56229 .

*M*<sup>∗</sup> = *M*<sup>1</sup> + *M*<sup>2</sup> = 1.053239, *V*<sup>∗</sup> = *V*<sup>1</sup> + *V*<sup>2</sup> + 2

Using the extended ERT-method we get the equivalent group:

Table 4. Accuracy of the Extended ERT-method for correlated streams.

probabilities the accuracy increases, but the absolute error decreases.

*L*∗ = 3.33306, *N*∗ = 3.44900 .

Therefore, using Erlang-B formula *M* = *L*<sup>∗</sup> · *E*(*N*<sup>∗</sup> + *K*, *L*∗).

channels:

**6. Conclusions**

system with blocking.

**7. References**


**7** 

*Indonesia* 

**Femtocell Performance Over** 

*1TELKOM R&D Centre, Bandung* 

*2Bandung Instittue of Technology, Bandung* 

**Non-SLA xDSL Access Network** 

H. Hariyanto1, R. Wulansari1, Adit Kurniawan2 and Hendrawan2

Femtocells are low-power wireless access points; operate in licensed spectrum and use residential or office DSL, cable or other broadband connections. Most mobile network operators (MNOs) offer femtocell access point (FAP) to retain their customers by improving indoor coverage and capacity. However in order to leverage massive femtocells deployment and generate new revenue, there should be business cases beyond the connectivity. Offering various femto services are crucial to strengthen customer value preposition and create new revenue generator for operators. Each service certainly requires a specific amount of bandwidth and QoS treatment. Therefore the study of bandwidth and QoS requirement for different traffic types are important, in order to design an optimum backhaul requirement

Heavy Reading in its report [1] stated that the cost of leased line for macrocell backhaul counted 25% of total MNO's capex. The need of small cells are paramount important in delivering high speed wireless broadband data. However the cost of new carrier-grade backhaul to support indoor base stations (IBSs) may increase depend on the new IBSs numbers and availability of leased lines. Femtocells utilize the existing broadband connection in the customer side. By this approach, the cost of backhaul can be reduced with the trade off fluctuation on the backhaul quality; if there is no specific service level

Bear in-mind that femtocell is a CPE with self configure capabilities, so that it will impose less interaction with mobile operators. For residential users, they may buy the femtocell from the mobile operator or electronic store and instantly plug it to the existing broadband connection at home. The users may not be aware of how the fixed-wireline operator will treat the femto traffic compared to other best-effort internet traffic. They may not be alert to that other broadband traffic traversed via the same home gateway will affect femtocell service performance. Bottleneck may occur anywhere in the network and affect femtocell

A comprehensive femtocell deployment guideline considering backhaul quality for 3G femtocell was addressed in [2]. The guideline describes the quality issue of VoIP services over 3G femtocell networks. VoIP services were observed as representation of real time

agreement (SLA) setup between MNO and internet service provider (ISP).

**1. Introduction** 

for femtocell.

performance.

