Huawei-LTE Network Design and Dimensioning Training Material

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(1)LTE Network Design and Dimensioning Training. HUAWEI TECHNOLOGIES (Thailand) CO., LTD..

(2) LTE Network Design and Dimensioning Training. Contents. Contents 01 LTE Radio Network Coverage Dimensioning 02 LTE Radio Network Capacity Dimensioning 03 LTE Cell Planning 04 LTE Access Transport Network Dimensioning. HUAWEI Confidential. Page1, Total1.

(3) LTE Radio Network Coverage Dimensioning.

(4) LTE Radio Network Coverage Dimensioning. Confidential Information of Huawei. No Spreading Without Permission.



(7) LTE Radio Network Coverage Dimensioning. . Before a network planning, we should firstly decide the planning targets, Which are important inputs for the planning. . The target service is the data service normally, the target quality of the data service is judged by the cell edge throughput. This throughput requirements are normally different in different target area, such as urban and rural.. . The coverage probability is according to the network deployment strategy, for different region ,such as dense urban and rural, we may apply different coverage probability.. . Target load affects not only the cell capacity, but also the coverage, since in different load conditions, the interference at of cell border is different also.. . Before planning, we should collect as much information as possible, such as to confirm if the indoor areas’ coverage is required, if TMA is used or not .... Confidential Information of Huawei. No Spreading Without Permission.


(9) LTE Radio Network Coverage Dimensioning. . The type of area will affect the pass loss during the link budget, including . Channel mode. . Indoor penetration loss. . Standard deviation of shadow fading margin. . Path loss factor. . Morphologies determines the propagation model formula using in cell radius calculation, as well as other parameters such as eNodeB antenna height and penetration loss. . Channel model has effect on the demodulation threshold and lead to difference cell radius. . ETU: Extended Typical Urban model. . EVA: Extended Vehicular A model. Confidential Information of Huawei. No Spreading Without Permission.


(11) LTE Radio Network Coverage Dimensioning. . Radio Network Dimensioning is a simplified analysis for radio network. . Dimensioning provides the first and most rapid evaluation of the network element number as well as the associated capacity of those elements. The target of dimensioning phase is to estimate the required site density and site configurations for the area of interest. Dimensioning activities include radio link budget and coverage analysis, capacity evaluation and final estimation of the amount of eNodeB hardware, cell average throughput and cell edge throughput.. . Objective: . . To obtain the network scale ( approximate eNodeB number and configuration). Method: . Select a proper propagation model, traffic model and subscriber distribution, and then estimate the eNodeB number, coverage radius, cell throughput, cell edge throughput and so on.. Confidential Information of Huawei. No Spreading Without Permission.

(12) LTE Radio Network Coverage Dimensioning. . Wireless network dimensioning intends to obtain the approximate EUTRAN scale. Based on the network dimensioning, geography and traffic distribution, the network is pre-planned in detail by using planning software and digital map.. . Based on the network dimensioning and site information, the initially selected LTE site is imported into the planning software, and coverage is estimated by parameters setting. Then an analysis is made to check whether the coverage of the system meet the requirements. If necessary, the height and tilt of the antenna and the eNodeB quantity are adjusted to optimize the coverage. And then the system capacity is analyzed to check whether it meets the requirement.. . Plan implementation parameters, such as antenna type / azimuth / tilt / altitude / feeder type / length …. . Plan cell parameters, such as tracking area planning, PCI planning, Neighbor relation planning, PRACH configuration planning…. Confidential Information of Huawei. No Spreading Without Permission.


(14) LTE Radio Network Coverage Dimensioning. . The carrier bandwidth of LTE could be 6RBs, 12RBs, 25RBs, 50RBs, 100RBs , the number of RB affects the cell border throughput directly. . MIMO is normally the different configuration in LTE, it can improve the LTE coverage and capacity, we should consider the gain of MIMO in planning. . MCS : Modulation & Coding Scheme, which is a radio channel auto adaptive algorithm . With high order MCS, the throughput can be higher, but it is not suitable in poor channel condition. So we have to select different MSC for different channel quality when calculating the coverage and capacity.. . 3GPP define a number of bands for LTE, so the propagation model should be selected accordingly.. Confidential Information of Huawei. No Spreading Without Permission.



(17) LTE Radio Network Coverage Dimensioning. . Generally, LTE has the same dimensioning procedure as the other wireless system. . In the coverage dimensioning, the link is estimated according to elements such as planned area, network capacity, and equipment performance in order to obtain the allowed maximum path loss. The maximum cell radius is obtained according to the radio propagation model and allowed maximum path loss. And then the site coverage area is calculated. Finally, the site quantity is calculated. Of course, the site quality is only for the ideal cell status, and some additional sites will be needed in actual terrain environment.. Confidential Information of Huawei. No Spreading Without Permission.




(21) LTE Radio Network Coverage Dimensioning. . Generally ,the max allowed path loss is calculated from the transmission power and the reception sensitivity.. . In the propagation, the Losses are normally static , such as penetration loss, body loss and cable loss.. . The gains (e.g. antenna gain, MIMO gain) can improve the max allowed path loss , since it enhances the signal strength or it can bring some compensation to the losses.. . The margins are reserved to ensure the coverage performance. With the margin revered , the coverage( calculated by link budget) can always satisfy the planning target even in case of the cell is loaded or in somewhere the slow fading is greater than the average value.. Confidential Information of Huawei. No Spreading Without Permission.

(22) LTE Radio Network Coverage Dimensioning. . EIRP: Equivalent Isotropic Radiated Power. Confidential Information of Huawei. No Spreading Without Permission.

(23) LTE Radio Network Coverage Dimensioning. . The tx power of a site is normally called ERIP. It is the transmitting power level from the point of the site antenna.. . EIRP, Equivalent Isotropic Radiated Power. . Insertion loss here is caused by combiner, etc.. Confidential Information of Huawei. No Spreading Without Permission.


(25) LTE Radio Network Coverage Dimensioning. . In LTE system, OFDMA is used for resource allocation. For different BW, receiver sensitivity is different, so during the link budget, we should take the single RE as a uniform standard for calculation.. . eNodeB power is shared by all sub-carriers(REs). If more REs are configured, the RE power on each RE decreases.. . Power of each sub-carrier(RE) = Power of eNodeB / Num of sub-carrier. Confidential Information of Huawei. No Spreading Without Permission.

(26) LTE Radio Network Coverage Dimensioning. . The cell-specific reference signal is transmitted in all downlink subframes. The signal serves as a basis for downlink channel estimation, which is used for data demodulation.. . The power for the cell-specific reference signal is set through the ReferenceSignalPwr parameter, which indicates the Energy Per Resource Element (EPRE) of the cell-specific reference signal.. . PB indicator the power ratio between type B symbol and type A symbol, which is specified by 3GPP protocol Pb. Symbol B/ Symbol A 1 ANT port. 2 or 4 ANT ports. 0. 1. 5/4. 1. 4/5. 1. 2. 3/5. 3/4. 3. 2/5. 1/2. Confidential Information of Huawei. No Spreading Without Permission.

(27) LTE Radio Network Coverage Dimensioning. . Relative command. Confidential Information of Huawei. No Spreading Without Permission.

(28) LTE Radio Network Coverage Dimensioning. . The presentation of PDSCH power . . Regarding power control for the PDSCH, the OFDM symbols on one slot can be classified into two types. Above table shows the OFDM symbol indexes within a slot where the ratio of the EPRE to the EPRE of RS is denoted by ρA or ρB.. Power control for the PDSCH determines the EPREs of different OFDM symbols using ρA and ρB. ρA determines the power offset against the power for the RS when there is no reference signal on the PDSCH, and ρB determines the power offset against the power for the cell-specific reference signal when there is a reference signal on the PDSCH.. Confidential Information of Huawei. No Spreading Without Permission.

(29) LTE Radio Network Coverage Dimensioning. . Related command:. Confidential Information of Huawei. No Spreading Without Permission.

(30) LTE Radio Network Coverage Dimensioning. . Related commands:. Confidential Information of Huawei. No Spreading Without Permission.



(33) LTE Radio Network Coverage Dimensioning. . In the allocated resource bandwidth and without any external noise or interference, the required minimum received signal level to fulfill the service quality requirement. . Thermal Noise is related to B/W and absolute temperature, it is calculated by this formula: 10LogB*T*W. . Noise figure is used for measuring the processing capability of the RF component for small signals.. Confidential Information of Huawei. No Spreading Without Permission.

(34) LTE Radio Network Coverage Dimensioning. . If the W=1Hz, Nth=-174dBm/Hz. . In LTE, the sub-carrier is 15kHz, the Nth =-132.2dBm/15kHz. Confidential Information of Huawei. No Spreading Without Permission.


(36) LTE Radio Network Coverage Dimensioning. . The ratio of useful signal to noise(SINR) is the key parameter in Rx sensitivity calculation and the representation of equipment performances of features.. . A certain service rate can be achieved by different combination of RB number(N RB) and MCS. More RBs with lower order MCS can achieve an equivalent rate with a case of less RBs with higher order MCS.. . In good channel condition, eNodeB can apply a higher order modulation and higher ratio channel coding , then more bits(from a TB) can be carried in a RB. In poor channel condition, eNodeB may have to apply QPSK modulation and add more channel coding redundant bits to overcome the channel fading and interference. That is to say, less bits(from a TB) can be carried.. Confidential Information of Huawei. No Spreading Without Permission.

(37) LTE Radio Network Coverage Dimensioning. . It is very important to select a reasonable target service rate and design the proper MCS and RB number to balance coverage and capacity.. . There are 29 levels of MCS for both uplink and downlink which is consistent with the eNB implementation.Basically, once the edge MCS is chosen, the cell coverage does not vary too much. The default MCS is acquired from system-level simulation.. Confidential Information of Huawei. No Spreading Without Permission.

(38) LTE Radio Network Coverage Dimensioning. . Based on the channel condition, eNodeB decides the modulation and informs the UE by MCS index.. . According to the MCS index, UE can check the TBS index also.. . According to the TBS index and RB number, UE can finally get the size of the TB.. . TB: Transport block. . TBS: TB size. Confidential Information of Huawei. No Spreading Without Permission.

(39) LTE Radio Network Coverage Dimensioning. . The TB size is checked according to the TBS index and RB number.. . Since the TB is the scheduled data per 1ms, so service rate can be calculated from the TB size. . . Service rate = TB size(bits) / 1ms. In this table, different combinations of NPRB and ITBS may be of the same TB size(such as the TB size 208).. Confidential Information of Huawei. No Spreading Without Permission.

(40) LTE Radio Network Coverage Dimensioning. . For the typical service rates, the required SINR is listed here.. . The figures are from simulation of ETU3 channel model.. . Channel Model is defined below:. Channel Model. # of channel tap. Maximum tap delay. Extended Pedestrian A (EPA). 7. 410 ns. Extended Vehicular A model (EVA). 9. 2510 ns. Extended Typical Urban model (ETU). 9. 5000 ns. Extended Vehicular A model ( EVA) tap delay [ns] 0 30 150 310 370 710 1090 1730 2510. Relative power [dB] 0.0 -1.5 -1.4 -3.6 -0.6 -9.1 -7.0 -12.0 -16.9. Extended Pedestrian A model ( EPA) tap delay [ns] 0 30 70 90 110 190 410. Relative power [dB] 0.0 -1.0 -2.0 -3.0 -8.0 -17.2 -20.8. Extended Typical Urban model ( ETU) tap delay [ns] 0 50 120 200 230 500 1600 2300 5000. Relative power [dB] -1.0 -1.0 -1.0 0.0 0.0 0.0 -3.0 -5.0 -7.0. Confidential Information of Huawei. No Spreading Without Permission.

(41) LTE Radio Network Coverage Dimensioning. . Rx Sensitivity . . Total Rx Gain . . In the allocated resource bandwidth and without any external noise or interference, the required minimum received signal level to fulfill the service quality requirement Antenna Gain, TMA Gain. Total Rx Loss . Feeder loss. . The noise figure can be gotten from the vendor.. . The thermal noise is calculated based on the bandwidth , temperature and the Boltzmann Constant. Confidential Information of Huawei. No Spreading Without Permission.


(43) LTE Radio Network Coverage Dimensioning. . Interference margin is reserved to prevent the noise caused by the power from neighboring cells after the network is loaded. . Shadow fading margin is reserved to prevent some unexpected deep fading.. Confidential Information of Huawei. No Spreading Without Permission.

(44) LTE Radio Network Coverage Dimensioning. . The IM is added to the link budget to compensate the interference from the loaded neighboring cells. . The higher load allowed, the larger interference margin specified.. . In the formula:. . . I: interference from neighbors. . N: thermal noise. . PRE: Transmission power of a RE. . QDL: target downlink load. . f: neighboring interference factor. . L: Downlink Coupling loss. Interference margin is usually gotten from the simulation.. Confidential Information of Huawei. No Spreading Without Permission.

(45) LTE Radio Network Coverage Dimensioning. . Slow Fading --- Signal levels obey Log-Normal distribution. . Propagation models predict only mean values of signal strength , the mean value of signal strength fluctuates.. . Probability that the real signal strength will exceed the average one on the cell border is around 50%,for higher than 50% coverage probability.. . In order to satisfy the required coverage probablity, an additional margin has to be introduced. The margin is called slow fading margin. SFM required. Coverage Probability @ Cell Edge:. Probability Density. P COVERAGE (x) = P [ F(x) > Fthreshold ]. Without SFM With SFM. Fthreshold. Received Signal Level [dBm]. Confidential Information of Huawei. No Spreading Without Permission.

(46) LTE Radio Network Coverage Dimensioning. . The standard deviation is a measured value that is obtained from various clutter types. It basically represents the variance (log-normally distributed around the mean value) of the measured RF signal strengths at a certain distance from the site.. . Therefore, the standard deviation would vary by clutter type. Depending on the propagation environment, the log-normal standard deviation can easily vary between 6 and 8 dB or even greater. Assuming flat terrain, rural or open clutter types would typically have lower standard deviation levels than the suburban or urban clutter types. This is due to the highly obstructive properties encountered in an urban environment that in turn will produce higher standard deviation to mean signal strengths than that experienced in a rural area. Standard Deviation of slow fading is related with morphology, frequency and environment.. SFM required. Coverage Probability @ Cell Edge:. Probability Density. P COVERAGE (x) = P [ F(x) > Fthreshold ]. Without SFM With SFM. Fthreshold. Received Signal Level [dBm]. Confidential Information of Huawei. No Spreading Without Permission.


(48) LTE Radio Network Coverage Dimensioning. . If there is no indoor system, then the indoor areas are covered by the outdoor sites, the standard deviation of the fading should include the standard deviation of outdoor slow fading and standard deviation of penetration loss. The calculation of the standard deviation is:. Z. X 2 Y 2.  standard deviation of slow fading 2  standard deviation of penetration loss2. Confidential Information of Huawei. No Spreading Without Permission.

(49) LTE Radio Network Coverage Dimensioning. . Penetration Loss is related to the radio frequency and material.. Confidential Information of Huawei. No Spreading Without Permission.

(50) LTE Radio Network Coverage Dimensioning. . Due to orthogonal subcarriers in OFDM system, only hard handover is support in LTE.. . Hard handover can lower the Rx signal strength requirement and outage probability at cell edge, which can bring a for coverage.. Confidential Information of Huawei. No Spreading Without Permission.






(56) LTE Radio Network Coverage Dimensioning. . In UL link budget calculation, most of the factors are the same with that of downlink, just several differences should be considered: . UE Tx power is normally 23dBm as protocol defined.. . In uplink ,the actual working bandwidth depends on the eNodeB's scheduling. . . In uplink, the noise figure of the eNodeB is different from the UE’s , which affects the uplink MRRSS. In uplink, interference is from other UE, it depends on the distribution of other UEs . So the gain of the ICIC algorithm is different also.. Confidential Information of Huawei. No Spreading Without Permission.




(60) LTE Radio Network Coverage Dimensioning. . Rx Sensitivity . In the allocated resource bandwidth and without any external noise or interference, the required minimum received signal level to fulfill the service quality requirement. . Rx Gain . . Rx Loss . . Antenna Gain, TMA Gain. Feeder loss, connector loss. The noise figure can be gotten from the vendor.. Duplex Mode Frequency Band Huawei eNodeB NF. . Huawei FDD eNodeB. Huawei TDD eNodeB. 2.3G or Lower. AWS. 2.6G. All the frequency band. 2.3. 2. 2.5. 4. The thermal noise is calculated based on the bandwidth , temperature and the Boltzmann Constant:. Confidential Information of Huawei. No Spreading Without Permission.



(63) LTE Radio Network Coverage Dimensioning. . The uplink interference is from the users in neighboring cell who are allocated with the same frequency and time resource.. . The interference margin is related to the distribution of the cell border users, so the value is from the simulation.. Confidential Information of Huawei. No Spreading Without Permission.


(65) LTE Radio Network Coverage Dimensioning. . White noise: White noise is noise whose power spectral density is evenly distributed over the entire frequency or space domain.. . Colored interference: Colored interference is interference whose power spectral density is not evenly distributed over the entire frequency or space domain.. . The MRC receiver maximizes the power of useful signals instead of reducing the power of interference. In high interference environments, however, reducing the power of interference is more effective, which is the basic for the IRC receiver concept. The IRC receiver adjusts antenna weights to make a tradeoff between reducing the power of interference and maximizing the power of the useful signal, thereby maximizing the SINR.. . The performance of the IRC algorithm depends on the interference characteristics. Only spatially colored interference can be mitigated by the IRC algorithm. In addition, the performance of the IRC algorithm depends on the accuracy of interference characteristics estimation.. . The IRC algorithm is not recommended in the following cases: . . Interference channels and signal channels are highly correlated. In this case, interference cannot be separated from useful signals, and the performance of the IRC algorithm is worse than that of the MRC algorithm. Interference is spatially white, or interference is very weak, similar to white noise. In this case, the IRC algorithm is equivalent to the MRC algorithm theoretically. The performance of the IRC algorithm, however, is worse than that of the MRC algorithm because of factors such as estimation errors in interference characteristics.. Confidential Information of Huawei. No Spreading Without Permission.


(67) LTE Radio Network Coverage Dimensioning. . With the propagation model, we can then obtained the maximum cell radius the maximum allowed path loss。. Confidential Information of Huawei. No Spreading Without Permission.






(73) LTE Radio Network Coverage Dimensioning. . The edge MCS can be adjusted to balance the coverage between DL and UL, if . DL coverage > UL coverage, then increase MCS index with one step. . DL coverage < UL coverage, then decrease MCS index with one step. Confidential Information of Huawei. No Spreading Without Permission.










(83) LTE Radio Network Capacity Dimensioning.

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(98) One session includes many packet calls, and one packet call includes many packets..

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(100) The Web model is the most complicated in all models. The measurement for HTTP services indicate that large web pages are formed by relatively small objects. That is to say, each page consists of some web embedded objects, such as main page, embedded image, and embedded Java program. In a package call, package service characteristics are related to the Web server and browser HTTP version. Currently, HTTP/1.0 and HTTP/1.1 are used. The maximum difference of the two versions are that the TCP connection of transmission layer of main object and embedded object are different. In HTTP/1.0, each main object and embedded object of the Web page download use different TCP connections. In the browsing process of most customer terminals, embedded objects use multiple TCP connections at the same time, which is called HTTP/1.0 - burst mode transmission. Meanwhile, the maximum TCP number can be connected is configurable. Most browser is set to 4. When the embedded object exceeds the number, a new TCP connection is set up, and the original connection is built. TCP overhead and congestion control is based on each object. In HTTP/1.1, consecutive TCP connections are used to download object. That is, the transmission object connected in serial on a single TCP connection is called HTTP/1.1 -consecutive mode transmission. TCP overhead and congestion control are based on each connection..

(101) Outlook email is used mostly on the market. The outlook transmission is dependent on remote procedure call (RPC) and uses complex protocols. When invoking the Outlook, there are 11 activated TCP connections. Each email processing consists of multiple MAPI segment elements. Each MAPI segment processing can be divided into more specific segments.

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(109) Single User Throughput in Busy Hour = PPP Session Time (s) x PPP Session Duty Ratio x Bearer Rate (kbit/s) x [1/(1 - BLER)] x BHSA x Penetration Ratiox 2 ( /3600 According to the Erl, single-user busy hour throughput of VoIP service =Erl x Mean Bit Rate (kbps) x BHSA x Penetration Ratio.

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(130) LTE Cell Planning.

(131) LTE Cell Planning. Confidential Information of Huawei. No Spreading Without Permission.




(135) LTE Cell Planning. . The general process includes information collection, pre-planning, detailed planning, and cell planning. In the cell planning, main concerns are frequency planning, TA planning, PCI planning, and PRACH planning.. Confidential Information of Huawei. No Spreading Without Permission.


(137) LTE Cell Planning. . There are several new frequency band options for LTE, some of which are available now or should be within the next few years. These include the 700MHz, AWS (Advanced Wireless Services) and 2.6GHz bands, as well as the re-use of existing GSM 900MHz and 1800MHz bands. In addition, due to poor harmonization, there are other spectrum bands available, including: 850MHz, 1500MHz, 1700MHz and 1900MHz.. Confidential Information of Huawei. No Spreading Without Permission.



(140) LTE Cell Planning. . Application scenario: Adapt to situations with integrated operator frequency resources and consecutive frequency bands. If the frequency point bandwidth is wide (>=10MHz), it can be used as the initial network construction mode of the urban or densely-populated urban areas. Basically satisfy the phase one capacity requirements. Use relatively narrow frequency point bandwidth (<=10MHz) to implement wide coverage of suburban and rural areas; thus reducing the initial network construction cost.. Confidential Information of Huawei. No Spreading Without Permission.

(141) LTE Cell Planning. . Application scenario: . . Adapt to situations that the operator frequency resources are rich or frequency bands dispersed and bandwidth is narrow. The system capacity is dependent on the bandwidth of single frequency point. If the bandwidth of frequency point is wide (>=5MHz), it can be used on initial network construction of dense or common urban. If the bandwidth of frequency point is narrow (<5MHz), it can be used on coverage of suburban and rural areas.. Confidential Information of Huawei. No Spreading Without Permission.

(142) LTE Cell Planning. . ICIC is a technology that mitigates inter-cell interference together with the scheduling and power control technologies. ICIC is applied at the Medium Access Control (MAC) layer. ICIC restricts highly interfering CEUs within the orthogonal bands at the edge of cells or schedules the CEUs in neighboring cells at different points of time. In this way, ICIC mitigates inter-cell interference, increases the CEU throughput, and improves the system coverage. This document provides the details on ICIC.. Confidential Information of Huawei. No Spreading Without Permission.


(144) LTE Cell Planning. . TA: Similar to the location area and routing area in 2G/3G networks, the tracking area (TA) is used for paging. TA planning aims to reduce location update signaling caused by location changes in the LTE system.. . TA list : A list of TAIs that identify the tracking areas that the UE can enter without performing a tracking area updating procedure. The TAIs in a TAI list assigned by an MME to a UE pertain to the same MME area. In LTE system, if an UE changes the TAs in the TAI list, TA update won’t be triggered.. Confidential Information of Huawei. No Spreading Without Permission.

(145) LTE Cell Planning. . In the Los Angles, there are several independent density area that connected by the main road (like island) . The UE may go across the different area through this road.. Confidential Information of Huawei. No Spreading Without Permission.


(147) LTE Cell Planning. . In this scenario, users are average distributed in each area. Confidential Information of Huawei. No Spreading Without Permission.


(149) LTE Cell Planning. . A TA coverage should be proper setting according to the capability of EPC. . When the suburban area and urban area are covered discontinuously, an independent TA is used for the suburban area.. Confidential Information of Huawei. No Spreading Without Permission.








(157) LTE Cell Planning. . PCI: Physical Cell ID, is used to generate scrambling code to identify the different cell. Confidential Information of Huawei. No Spreading Without Permission.


(159) LTE Cell Planning. . Differences between a scrambling code and a PCI: The scrambling code ranges from 0 to 511 whereas the PCI ranges from 0 to 503. In addition, the protocols do not have specific requirements for scrambling code planning. Therefore, only the reuse distance needs to be ensured in scrambling code planning. For PCI planning, however, 3GPP protocols require that the value of PCI/3 should be 0, 1, or 2 in each eNB.. Confidential Information of Huawei. No Spreading Without Permission.








(167) LTE Cell Planning. . A CP is a copy of the end of an OFDM symbol to the start position of the symbol. Each CP generates a guard interval between two OFDM symbols.. Confidential Information of Huawei. No Spreading Without Permission.

(168) LTE Cell Planning. . The symbol energy that can be captured by the OFDM receiver depends on the CP length: . . If the CP is longer than the multipath delay of an OFDM symbol, the OFDM receiver can capture all energy of the symbol. If the CP is shorter than the multipath delay of an OFDM symbol, the OFDM receiver can capture only some energy of the symbol.. Confidential Information of Huawei. No Spreading Without Permission.


(170) LTE Cell Planning. . The random access procedure is used in various scenarios, including initial access, handover, or re-establishment. Like other 3GPP systems the random access procedure provides a method for contention and non-contention based access. The PRACH (Physical Random Access Channel) includes RA (Random Access) preambles generated from ZC (Zadoff-Chu) sequences.. . There are five preamble formats defined which four of them are for FDD. Confidential Information of Huawei. No Spreading Without Permission.

(171) LTE Cell Planning. . Other preamble formats then Format 0 and Format 4 (TDD) are available only with the LOFD-001009 Extended Cell Access Radius feature.. Confidential Information of Huawei. No Spreading Without Permission.

(172) LTE Cell Planning. . c = speed of light (300000km/h). Confidential Information of Huawei. No Spreading Without Permission.




(176) LTE Cell Planning. . * in fact, with the lowest configuration, where we assume maximum cell radius of 790m we assign only one value per cell. Further explanation on following slides.. Confidential Information of Huawei. No Spreading Without Permission.

(177) LTE Cell Planning. . . PRACH configuration is defined by the following parameters . Root sequence, setting in the eNodeB. . Ncs: Automatically setting based on the cell radius configuration. . PRACHfrequency offset: Scheduled by eNodeB. . High speed flag: Indicate whether the cell is for high speed. All the parameters all carried by Sib2. Confidential Information of Huawei. No Spreading Without Permission.


(179) LTE Cell Planning. . Calculations:. ZeroCorrZone. Ncs. Preamble Format. T_GT (ms). 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15. 839 13 15 18 22 26 32 38 46 59 76 93 119 167 279 419. 3 0 0 0 0 0 0 0 0 0 0 0 2 2 1 1. 715.625 96.875 96.875 96.875 96.875 96.875 96.875 96.875 96.875 96.875 96.875 96.875 196.875 196.875 515.625 515.625. Max Delay Max Cell Radius Max Cell Radius Spread [ms] (according to T_GT) [km] (according to Ncs) [km] 16.666 5.208 5.208 5.208 5.208 5.208 5.208 5.208 5.208 5.208 5.208 5.208 5.208 5.208 16.666 16.666. 107.344 14.531 14.531 14.531 14.531 14.531 14.531 14.531 14.531 14.531 14.531 14.531 29.531 29.531 77.344 77.344. 117.214 0.792 1.078 1.507 2.079 2.651 3.510 4.368 5.512 7.371 9.803 12.234 15.953 22.818 37.119 57.143. Confidential Information of Huawei. No Spreading Without Permission.


(181) LTE Cell Planning. . Here is an another example for the root sequence planning, suppose the cell radius is 10km . . The Ncs value is determined by the cell radius. If the cell radius is 9.8 km, the Ncs value is 76 The value of 839/76 is rounded down to 11, that is, each index can generate 11 preamble sequences. In this case, six root sequence indexes are required to generate 64 preamble sequences..  . The number of available root sequence indexes is 139 (0, 6, 12…828) The available root sequence indexes are assigned to cells. The assignment principles are similar to those for PCIs.. Confidential Information of Huawei. No Spreading Without Permission.




(185) LTE Cell Planning. . Meaning: Indicates the ratio of UL subframes to DL subframes in a TDD cell. For details, see 3GPP TS 36.211.. . GUI Value Range: SA0(SA0), SA1(SA1), SA2(SA2), SA3(SA3), SA4(SA4), SA5(SA5), SA6(SA6). . Unit: None. . Actual Value Range: SA0, SA1, SA2, SA3, SA4, SA5, SA6. Confidential Information of Huawei. No Spreading Without Permission.





(190) LTE Access Transport Network Dimensioning.

(191) LTE Access Transport Network Dimensioning. Confidential Information of Huawei. No Spreading Without Permission.




(195) LTE Access Transport Network Dimensioning. . The eNodeB communicates with other NEs through the following five major interfaces: . . . . . The S1 interface exists between the eNodeB and the S-GW/MME. One eNodeB supports a maximum of 16 S1 interfaces. The X2 interface exists between the eNodeBs. It mainly implements the X2 handover function. One eNodeB supports a maximum of 32 X2 interfaces. The OM interface, also known as the OM channel, exists between the eNodeB and the network management system. The clock interface, also known as the clock channel, exists between the eNodeB and the IP clock server. The eNodeB, functioning as the clock client, obtains the system clock from the clock packets that are periodically sent from the IP clock server. The co-transmission interface, also called co-transmission channel, exists between the eNodeB and other devices. Traffic of other devices is forwarded through the IP routing function of the eNodeB. The other device can be a GSM/CDMA/WiMAX/UMTS/LTE base station or an IP-based device.. Confidential Information of Huawei. No Spreading Without Permission.

(196) LTE Access Transport Network Dimensioning. . The S1 interface can be subdivided into the S1-MME interface supporting Control Plane signaling between the eNodeB and the MME and the S1-U Interface supporting User Plane traffic between the eNodeB and the S-GW.. . S1 application protocol supports following functions . . . .  . . . . E-RAB Management - this incorporates the setting up, modifying and releasing of the E-RABs by the MME. Initial Context Transfer - this is used to establish an S1UE context in the eNodeB, setup the default IP connectivity and transfer NAS related signaling. UE Capability Information Indication - this is used to inform the MME of the UE Capability Information. Mobility - this incorporates mobility features to support a change in eNodeB or change in RAT.. Paging S1 Interface Management - this incorporates a number of sub functions dealing with resets, load balancing and system setup etc. NAS Signaling Transport - this is used for the transport of NAS related signaling over the S1-MME Interface. UE Context Modification and Release - this allows for the modification and release of the established UE Context in the eNodeB and MME respectively. Location Reporting - this enables the MME to be made aware of the UEs current location within the network.. Confidential Information of Huawei. No Spreading Without Permission.

(197) LTE Access Transport Network Dimensioning. . X2 interface interconnects two eNodeBs and in so doing supports both a control plane and user plane. The principle control plane protocol is X2AP . This resides on SCTP where as the User Plane IP is transferred using the services of GTP-U and UDP .. . The function of X2 AP is shown as following: . Mobility Management - this enables the serving eNodeB to move the responsibility of a specified UE to a target eNodeB. This includes Forwarding the User Plane, Status Transfer and UE Context Release functions.. . . . . . Load Management - this function enables eNodeBs to communicate with each other in order to report resource status, overload indications and current traffic loading. Error Reporting - this allows for the reporting of general error situations for which specific error reporting mechanism have not been defined. Setting / Resetting X2 - this provides a means by which the X2 interface can be setup / reset by exchanging the necessary information between the eNodeBs. Configuration Update - this allows the updating of application level data which is needed for two eNodeBs to interoperate over the X2 interface.. For the SCTP and GTP, it performs the similar functions as it performs in S1 interface.. Confidential Information of Huawei. No Spreading Without Permission.


(199) LTE Access Transport Network Dimensioning. . IEEE1588 defines the PTP protocol, which applies to the standard Ethernet, with the precision to microseconds.IEEE1588 V2 released in 2008 mainly incorporates the improvements on higher frequency accuracy and less impact of the processing delay at the intermediate transport equipment.. . The IEEE1588 standard targets precise synchronization of distributed and independent clocks in measurement and control systems. In LTE applications, high-accuracy frequency synchronization and time synchronization between clock servers and eNodeBs can be achieved.. Confidential Information of Huawei. No Spreading Without Permission.

(200) LTE Access Transport Network Dimensioning. . When layer 1 network is adopted as the transport bearer network, the eNodeB and adjacent NEs are connected through the physical layer. The Synchronous Digital Hierarchy (SDH) network and Plesiochronous Digital Hierarchy (PDH) network are typical layer 1 networks. The eNodeB supports the access to the SDH/PDH network through the E1/T1 interface. The direct connection through the Ethernet interface, for example, the connection of the eNodeB and the S-GW through the GE optical cable is a layer 1 network. The following describes only the E1/T1 connection mode, because the direct connection mode is rare in the actual situations.. . As shown above, the layer 1 network provides only the bearer function on the physical layer, which is the simplest transport bearer mode. In this mode, the transmission to the upper layers is transparent. When using a layer 1 networking solution, users need to configure the related data concerning the physical layer, such as the attributes of the E1/T1 interface.. . The cost of renting the transport devices is usually high. In the case of the layer 1 network, the channels are allocated in fixed mode. Therefore, the bandwidth utilization is low. Besides, the bandwidth needs to be configured for each S1/X2 logical interface.. . The layer 1 transport bearer network is usually applied to the GSM/UMTS system that provides mainly the CS service. It is rarely applied to the LTE system that provides mainly the PS service.. Confidential Information of Huawei. No Spreading Without Permission.

(201) LTE Access Transport Network Dimensioning. . The layer 2 network is usually adopted as the transport bearer network of the LTE system. The layer 2 network in the LTE system is the Ethernet switching network. The major device is the Ethernet switch. The eNodeB accesses the Ethernet switching network through the FE/GE interface.. . As shown above, the layer 2 network provides the bearer function on the MAC layer. The MAC layer is the data link layer protocol of the Ethernet. Complying with the IEEE 802.3, the MAC layer provides addressing and data access control mechanisms.. Confidential Information of Huawei. No Spreading Without Permission.

(202) LTE Access Transport Network Dimensioning. . The layer 3 network in the LTE system is the IP routing network. The major device is the router. The eNodeB accesses the IP routing network through the FE/GE interface or the E1/T1 interface.. . As shown above, the layer 3 network provides the bearer function on the IP layer. Users need to configure the physical layer, data link layer, and IP layer.. . The configuration of the physical layer and data link layer involves the configuration of the E1/T1 interface and FE/GE interface.. . The configuration of the IP layer involves the configuration of the IP addresses, IP route list, and DiffServ.. . The layer 3 network is usually adopted as the transport bearer network of the LTE system.. Confidential Information of Huawei. No Spreading Without Permission.





(207) LTE Access Transport Network Dimensioning. . MAC provides the interface between the E-UTRA protocols and the E-UTRA Physical Layer. In doing this it provides the following services: . . Mapping - MAC maps the information received on the LTE Logical Channels into the LTE transport channels. Multiplexing - The information provided to MAC will come from a RB (Radio Bearer) or multiple Radio Bearers. The MAC layer is able to multiplex different bearers into the same TB (Transport Block), thus increasing efficiency.. . . HARQ (Hybrid Automatic Repeat Request) - MAC utilizes HARQ to provide error correction services across the air. HARQ is a feature which requires the MAC and Physical Layers to work closely together. Radio Resource Allocation - QoS (Quality of Service) based scheduling of traffic and signaling to users is provided by MAC.. Confidential Information of Huawei. No Spreading Without Permission.

(208) LTE Access Transport Network Dimensioning. . The RLC protocol exists in the UE and the eNodeB. As its name suggests it provides “radio link” control, if required. In essence, RLC supports three delivery services to the higher layers: . . . TM (Transparent Mode) - This is utilized for some of the air interface channels, e.g. broadcast and paging. It provides a connectionless service for signaling. UM (Unacknowledged Mode) - This is like Transparent Mode, in that it is a connectionless service; however it has the additional features of sequencing, segmentation and concatenation. AM (Acknowledged Mode) - This offers an ARQ (Automatic Repeat Request) service. As such, retransmissions can be used.. Confidential Information of Huawei. No Spreading Without Permission.

(209) LTE Access Transport Network Dimensioning. . PDCP (Packet Data Convergence Protocol) provides services to both the Control Plane and User Plane. The main PDCP functions include: . . Header compression and decompression of IP datagrams using the ROHC (Robust Header Compression) protocol. Maintenance of PDCP SN (Sequence Number) for radio bearers operating in RLC AM (Acknowledged Mode).. . In-sequence delivery of upper layer PDU (Protocol Data Units) at handover.. . Duplicate elimination of lower layer SDUs at handover for RLC AM radio bearers.. . Ciphering and deciphering of User and Control Plane data.. . Integrity protection and integrity verification of the Control Plane data.. . Discarding of data on a timeout basis.. . Discarding of data on a duplicate basis.. Confidential Information of Huawei. No Spreading Without Permission.

(210) LTE Access Transport Network Dimensioning. . In radio systems, the resources on the LTE-Uu interface are far more precious than the processing capability of processors. Therefore, ROHC is suitable for radio systems, even though it is complex compared with earlier schemes. It is mainly used for VoIP services.. . In LTE, the ROHC entity is located within the Packet Data Convergence Protocol (PDCP) entity on the user planes of the UE and the eNodeB, and is used only for the header compression and decompression of data packets on the user plane.. Confidential Information of Huawei. No Spreading Without Permission.


(212) LTE Access Transport Network Dimensioning. . GTP-U tunnels are used to carry encapsulated PDU (Protocol Data Unit) between endpoints or in the case of the X2 interface.. . Numerous GTP-U tunnels may exist in order to differentiate between EPS bearer contexts and these are identified through a TEID (Tunnel Endpoint Identifier).. . The average header for GTP-U is 12 bytes, consist of following part  . Version: Specify the GTP protocol version P flag: Indicate whether another GTPv2-C message with its own header and body shall be present at the end of the current message. . T flag: Indicate the presence or not of the TEID field.. . Message Type: Indicate the type of GTP message.. . TEID: Indicate the unique GTP channel. It is unique per EPS bearer for GTP-U and. per PDN connection for GTP-C. . Sequence Number: Allows in-order delivery of user plane PDU.. Confidential Information of Huawei. No Spreading Without Permission.



(215) LTE Access Transport Network Dimensioning. . Access control based on IEEE 802.1x ensure the authorized accesses of the eNodeB to the transport network. For details, see section ‎5.2 "Access Control Based on IEEE 802.1x." To adapt to the all-IP based transmission mode of the LTE system, the eNodeB uses the IPSec security mechanism to ensure the confidentiality, integrity, and availability of data transmission. IPSec services are the security services provided for the IP layer, and thus can be used by the upper-layer protocols such as the TCP, UDP, ICMP, and SCTP. IPSec is a protocol family used to guarantee the security for IP communication.. . For transmission of IP packets, IPSec guarantees high-quality and interoperable security based on cryptology. Ciphering and integrity verification are performed on the IP layer between specific communicating parties to guarantee the following security features of packet transmission: . . . . Data confidentiality: Ciphering protection is performed on user data, which is transmitted in ciphered text. Data integrity: The received data is authenticated to check whether or not the data is modified. Authentication: The data source is authenticated to guarantee that data is transmitted from an authenticated sender. Replay protection: The attack by unauthorized users, who repeatedly transmit the captured packets, is prevented. The party under the attack does not accept the old or repeated packets.. Confidential Information of Huawei. No Spreading Without Permission.

(216) LTE Access Transport Network Dimensioning. . IPSec supports two security protocols: the Authentication Header (AH) protocol and Encapsulation Security Protocol (ESP) protocol. The AH protocol performs integrity protection, and the ESP protocol performs both integrity protection and ciphering.. . IPSec supports two packet encapsulation modes: transport mode and tunnel mode. The difference between the transport mode and the tunnel mode is the IP packet protection scope. . . Transport mode: protects the effective payload and upper-layer protocols (ULPs) of IP packets. In transport mode, the IPSec headers (AH or ESP) are placed behind the IP header and before the ULPs. Tunnel mode: protects the security for original IP packets. In tunnel mode, the original IP packet is encapsulated into a new IP packet, and the IPSec header is inserted between the headers (AH and/or ESP) of the new and original IP packets. The header of the original IP packet is protected as part of the effective payload.. Confidential Information of Huawei. No Spreading Without Permission.

(217) LTE Access Transport Network Dimensioning. . Virtual Local Area Network (VLAN) is a data exchange technology derived from the traditional LAN.. . VLAN allows LAN devices to be logically grouped into multiple network segments (that is, smaller LANs) to implement virtual workgroups. The hosts in different VLANs are separated from each other and they communicate with each other only through routers. A VLAN is a broadcast domain, that is, a host in a VLAN can receive the broadcast packets from the other hosts in the same VLAN but cannot receive the broadcast packets from other VLANs. The VLAN attaches different labels to the operation, administration, and maintenance (OAM) data and the traffic data. Thus, differentiated services can be provided. The VLAN also provides services of different priorities and security levels on the MAC layer.. . The VLAN header consists of following parts: .   . TPID: Tag protocol identifier, indicate that it is the frame with 802.1Q, the value is fixed with 0x8100, the length is 2 bytes PRI: Priority indicator, 3 bits CFI: Canonical Format Indicator, 1 bit VLAN ID: Indicate which VLAN belongs to, 12 bits. Confidential Information of Huawei. No Spreading Without Permission.


(219) LTE IP Transport Design & Dimensioning. Confidential Information of Huawei. No Spreading Without Permission.

(220) LTE IP Transport Design & Dimensioning. . From the capacity dimensioning, we can get throughput of radio interface, including the overhead of radio interface. So the radio payload throughput can be calculated. During the IP transport, the additional overhead will be added, from the analysis of overhead, we can get the throughput of transport layer.. Confidential Information of Huawei. No Spreading Without Permission.

(221) LTE IP Transport Design & Dimensioning. . PDCP: Packet Data Convergence Protocol, perform data integrity check and ciphering function.. . ROHC: Robust of head compression, it is a kind of head compression technology. . RLC: Radio link control protocol. . MAC: Perform scheduling control function. . CRC: Cyclic redundancy check. Confidential Information of Huawei. No Spreading Without Permission.





(226) LTE IP Transport Design & Dimensioning. . The LMPT provides four Ethernet interfaces, that is, two optical interfaces (SFP, 100/1000BASE-FX) and two electrical interfaces (RJ45, 10/100/1000BASE-TX). Two interfaces can be used in combined mode. Multi-mode optical cable or single-mode optical cable can be used according to the type of the optical module.. Confidential Information of Huawei. No Spreading Without Permission.


(228) Course Name. Confidential Information of Huawei. No Spreading Without Permission. N-39.

(229) LTE IP Transport Design & Dimensioning. Confidential Information of Huawei. No Spreading Without Permission.

(230)

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