Carrier Current Line Systems Technologies in M 2 M Architecture for Wireless Communication

This paper investigates the Carrier Current Line Systems (CCLS) technologies of Machine to Machine (M2M) architecture which applied for mobile station coverage working with metro, high speed railway, and subway such as analysis for public transport of an indoor transition system. It is based on the theory and practical engineering principle which provide guidelines and formulas for link budget design to help designers fully control and analyze the single output power of uplink and downlink between Fiber Repeaters (FR) and mobile station as well as base station. Finally, the results of this leakage cable system are successfully applied to indoor coverage design for metro rapid transit system which are easily installed cellular over fiber solutions for WCDMA/LTE access is becoming Ubiquitous Network to Internet of Thing (IOT) real case hierarchy of telecommunication.


Introduction
This paper investigates the CCLS which are applied to radio frequency (RF) over CCLS technologies of M2M architecture for wireless communication based on telecommunication certification body (TCB) workshop Santa Clara, CA, Steve Martin office of engineering and technology equipment authorization Branch Federal Communications Commission (FCC) laboratory, in which CCLS rules are applicable to Radio Over Fiber (ROF) [1,2] and can access devices operating from 700 MHz to 2100 MHz [3,4].
The definition of CCLS includes use of the transmission line between substation and customer terminal device.CCLS are a part of systems that transmits RF energy by conduction or radiation [5].CCLS convergence is a trend that fits right in with wireless communication adoption and the benefits of modularization and interoperability.CCLS infrastructure can easily solve the performance, reliability, and compatibility of these systems which operators believe will improve transmission questions.Small pico cell environments with low capital costs and low risk allow operators to try these systems.Rather than using them in a large macroenvironment that would gobble up significant amounts of money as well as increase risk, operators see the advantage of a carrier current line systems.
ROF convergence is a trend that fits right in with wireless communication adoption and the benefits of modularization and interoperability.ROF infrastructure can easily solve the performance, reliability, and compatibility of these systems which operators believe will improve transmission questions.
This paper is organized as follows.The design rules of carrier current line systems are illustrated in Section 2. Then studies of the key factors and solution of the fiber repeater will be discussed in Sections 3 and 4, respectively.Finally, the conclusion is made in Section 5.

Design Rules of Carrier Current
Line Systems  The MOU [6] system block diagram is illustrated in Figure 2. Because the RF signals coming from the Base Transceiver Station (BTS) in DL are approximately +13 dBm [7]; the signal level would be attenuated for E/O module receiving.The optical signals are separated into multichannel signals by ROUs.Therefore, the RF DL module is composed of adjustable digital attenuator and splitter.
When MOU receives optical signals from ROU through O/E optical modules, the RF signal conversions are processed in UL RF modules.Therefore, the RF module is composed of an adjustable digital attenuator and combiner.It distributes the UL signals power which is an attenuated RF signal level in BTS noise floor ≦ −121 dBm.Because BTS services a lot of mobile stations, input noise signal, which is above −121 dBm, will block communication of weak signal cellular phones and drop calls rating.
The ROU [8] block diagram is shown in Figure 3, the remote optical unit in a wireless terminal serves the mobile station (MS).
In the part of DL, the O/E module of ROU receives optical signal from the MOU and converts the optical signal into RF signal.Then the RF signal is amplified by power amplifier and transmitted through the antenna.So the basic DL architecture of ROU is the combination of O/E module, IF filtering high frequency conversion module, and power amplifier module.As the same principle, in the part of UL, (1) Path Loss.Friis free space equation [9] can be written as where,   () is the transmitter antenna and the distance  is the reception power of the receiver.  is transmitter power.  is transmitter antenna gain.  is receiver antenna gain. is wavelength of the signal. is transmitter and receiver distance. is system loss factor.Based on the Fraunhofer distance [10], can be written as where  is the maximum size of the antenna.  is Fraunhofer distance;   must meet the following two conditions: > ,   > , and the propagation mode in the Large Scale reception power of the distance  0 . >  0 >   ,   ( 0 ), and the predicted point than the distance  is the reception power When they meet the conditions set, see the following formula: (2) Link Budget between BTS and MS.The calculation of link budget parameter is as shown in Table 1.
BTS and MS sensitivity () is the minimum noise floor ( min ) and noise figure (NF) and minimum Signal to Noise ratio (/) min.The sum can be expressed as below: At least of working on service in a telecommunication field the maximum RF uplink path loss signal can be written as where PL UL,max is maximum RF uplink path loss signal. O.MS is output power of the MS. BTS is the sensitivity of BTS.
The maximum RF DL path loss signal can be written as where PL DL,max is the maximum downlink path loss. O.BTS is BTS output power. MS is mobile station sensitivity.Therefore, the most path loss in discrepancy of the bidirection imbalance (Imb) can be expressed as According to the standard of IS95 Technical Specification is divided in a calculation of link budget processing:

Studies of the Key Factors
In a cellular communication M2M system between BTS and MS, an added FR thermal noise signal brings BTS to reduce receiving sensitivity.

Calculation Gain of a Fiber
Repeater.The use of a FR in a wireless communication network causes leveling on BTS from which the FR receives the RF signal.In uplink a high interfering signal power at the BTS receiver will cause a service restriction on the MS that is able to transmit a signal whose power will guarantee the required   / 0 , where   is energy bit and  0 is spectral noise density.In DL this effect will cause the same problem to the MS receiver.The thermal noise power,  th , can be expressed as where  is Boltzmann's constant (1.38 × 10 −23 J/K). is absolute temperature (290 ∘ K).  is signal bandwidth (200 KHz/Channel).
The thermal noise power of the BTS receiver can be expressed as where NF bts is noise figure of the BTS (2 dB). bts is thermal noise power;  bts = 10 log[] + NF bts = −121 dBm/Hz + 2 dB = −119 dBm.When injected by the FR optical link in correspondence with power sources from BTS, the thermal noise power that BTS receives is the noise figure of the BTS receiver  bts and thermal noise power of the FR.

Injected by Fiber Repeater of BTS Deviation.
In UL, a high interfering signal power at the BTS receiver will cause a service restriction to the MS  that is able to transmit a signal whose power will guarantee the required   / 0 .In particular, the FR which is an active component that will amplify the signals coming from transmission interfering signal due to thermal noise power.Therefore, the output noise power of FR,  rep , can be expressed as where  rep is thermal noise power of the FR. bts is thermal noise power of the BTS receiver.NF rep is noise figure of the FR. rep is gain of the FR.All of the path loss from BTS to FR is Lp.Therefore, the thermal noise power signal injected by the FR due to BTS receiver,   rep , can be written as When FR is injected in BTS receiver, the total noise power is  bts -total [11] and should be satisfied as Assume that where  bts -total =  bts + Δ bts .
The above analysis can demonstrate that the injected FR in BTS receiver increases the noise power than one without FR.Furthermore, there are many factors that affect noise floor in BTS receiver.
The related parameters include the noise figure of BTS, noise figure of the FR, the gain of FR, and the path loss from BTS to FR.The equation can be written as (13).
When NF rep −NF bts + rep −  = 0, then the noise floor has increased Δ bts , which equals 3 dB, in receiver port of BTS.
When NF rep − NF bts +  rep −   = −6, then the noise floor has increased by Δ bts , which equals 0.97 dB, in receiver port of BTS.Therefore, the invaded FR is not an influence on BTS receiver.
In general, the noise figure of NF bts is 2 dB.Following (10), the thermal noise power signal injected by the FR due to BTS received  rep is −125 dBm.
In the engineering practice, the noise figure of BTS and FR is constant, the noise floor increase of BTS receives port, and Δ bts has an influence on the path loss of the BTS transmitter to FR and FR  rep .
The noise figure of BTS, NF bts , is 2 dB.The noise figure of FR, NF rep , is 5 dB as usual.The gain of FR,  rep , should be lower than 8 dB path loss.By limiting  rep , the Δ bts would be controlled under 1 dB.
In the network design, if the range of the objective coverage is relatively great, it needs to connect in parallel to a lot of FR.In this case, the noise floor of BTS receiver,  btstotal, is the noise figure and the thermal noise power signal injected by the FR due to BTS receive port,   rep is shown to be  rep -total = 10 log[10 bts + 10(  rep )].The quantity of FR is .In order to control the  rep -total, the Δ bts must be under 1 dB.The BTS noise floor has increased by FR as shown in Table 2.
The Δ bts signal increment by FR due to the BTS receiver is equal.For case of  FR  injected in BTS receiver, the noise power   rep , contributed by one of FR  , should be followed as   rep < −125 − 10 log  .If every one of the FR  has the same path loss   , the FR gain in  FR  is smaller than one in one FR.In  FR  , the dropped value for FR gain is about 10 log  .Generally, UL gain of FR is set in BTS receiver by some considerations: (1) path loss   from BTS transmitter to FR, (2) numbers of FR in parallel to BTS receiver.
In general, the FR directly couples to signal, which comes from BTS, and the path loss of FR is   for the coupling of the coupler.The same principle, UL of FR gains, needs more than a small coupling loss about 8 dB.
It should need two parallel FR  for practice.In general, choose a high coupling ratio of coupler, when the input optic fiber signal of FR is 0 dBm.Therefore, the path loss coming from BTS to FR is 39 dB.The FR of UL gain is 31 dB, so a FR invades the BTS receive port of sensitivity that is not influenced.The calculation of the UL budget of FR is shown in Table 3.

Link Budget of FR and MS.
The implementation of FR of DL gain is to control the output power of the FR, which has considered between FR and  system equilibrium [12].For the equilibrium of guaranteeing to UL and DL the transmission power, the FR should be satisfied as where Therefore, the maximum FR output power is  o-rep = 33 + 6 − 5 = 34 dBm.Attention should be paid to the DL budget of FR.In the case of FR practical, when implementation of a gain adjustment has been considered, isolation between FR and the antenna prevents FR from local oscillations.(1) Indoor Coverage Requirements and Inspection Methods.Measurements are performed at three different areas having installed with MRT underground environment includes multiservices stations and tunnels of quality [11] plan in indoor coverage requirements and acceptances as in Table 4.

Solution of the Fiber Repeater
(2) System Structure and Link Budget.The system network structure needs tunnel environment factor and signal objective coverage plan [13] as shown in Figure 4.
(3) Power Spectrum Density of Calculations.R4 to R4A LC is installed at well number four of south and north tunnel is one, respectively, LC connected to ROU output port [14,15].In used to R4 to R4A, for example, as shown in Figure 5 the FR system structure.
R4 Station [R4 to R4A] Control room of POI + MOU × 1, / tunnel intersection exit ROU × 2. Control room, intersection exit and system network plan calculation of link budget [11,12].As shown in Figure 6 System network plan and calculation of link budget of Machine to Machine (M2M) architecture.

Station R4 to 4A of Power Spectrum Density
R4 Station.195 m, R4 Station BTS provided R4 to R4A in tunnel signal coverage.Control room to tunnel exit is 181 m, 1-5/8  coaxial cable loss is 8 dB, and tunnel length is 1,600 m.
Intersection.FR of two types of ROU equipment are installed number of the south and north tunnel is one, respectively, Point of Interface (POI) output port connects to MOU.MOU output ports connect fiber cable to intersection ROU input port.R4 to R4A leakage cable is installed at well number three of south and north tunnel is one, respectively, leakage cable connected to ROU output port.In used to R4 to R4A, for example, as shown in Figure 5.

Measurement of the Practice
(1) System Structure and Quality Plan.The system network structure while need to tunnel environment and signal objective of cell coverage plan as shown in Figure 5 and Table 4.
(2) The Tool of Measurements.The wireless communication system from MRT measure of service quality index coverage, blocking rate, and dropped call rate is the QoS indicators.These results clearly show the mass transit environment and maintain good RxLev SQI with RxQual interrelated data such as the importance of quality of service.

Conclusion
An achievement of tunnel engineering in indoor coverage for CCLS design engineers and maintenance engineers properly performs planning analysis and maintenance operation based on abovementioned critical points; FR equipment can solve open area of transmission problem for indoor coverage of M2M architecture of wireless communications.This paper describes in detail FR's importance of design principles, including (a) the calculation of the gain; (b) the calculation of uplink and downlink power balance; (c) indoor coverage which the practice of design and measurement for acceptance procedure.
As long as design engineers and maintenance engineers properly perform planning analysis and maintenance operation based on abovementioned critical points, fiber repeater indeed can solve open area of transmission problem for indoor coverage of mobile communications.
This paper proves a complete practice of design and measurement results for wireless communication network configurations with a different distributed antenna system at the same time.These CCLS are a part of hybrid systems that transmit radio frequency energy by conduction over the communication media received by conduction and radiation infrastructure which are easily installed cellular over fiber solutions for WCDMA/LTE access that is becoming Ubiquitous Network to IOT real case hierarchy of telecommunication.
Future studies will include comparison of DAS and Femtocells in indoors, as well as network planning with indoor CDMA2000, WCDMA, and LTE at the same time to reduce the number of the eNode B implementation for high levels building and metro rapid transit system.

Figure 4 :
Figure 4: The MRT in building coverage of system network architecture.

Figure 6 :
Figure 6: System network plan and calculation of link budget of Machine to Machine (M2M) architecture.

Figure 8 :
Figure 8: RxLev with RxQual and SQI overview of the tunnel measurement analysis.

Table 1 :
The calculation of link budget parameter.

Table 3 :
The calculation of the link budget fiber repeater.
figure of MS is NF ms = 6 dB, and noise figure of FR is NF rep = 5 dB.
o-rep is FR of output power. o-ms is MS of output power.NF ms is noise figure of MS.NF rep is noise figure of FR.The maximum of the MS output power is  o-ms = 33 dBm, noise

Table 4 :
Requirements and acceptances of the quality plan in indoor coverage.Requirements and acceptances of the quality plan in indoor coverage