**3. Spectrum aspects of 5G satellite segment use**

On the one hand, spectrum and wide bandwidth for 5G terrestrial networks will require utilization of millimeter-wave (mm-wave) bands to provide data transfer speed reaching up to 20 Gigabits per second in 5G radio interface connect with the process of delivery of the extended broadband mobile access (eMBB) service. On other hand such requirements to use frequency channels with bandwidth from 50 up to 400 MHz for eMBB-services can provide only in mm-wave bands which already utilized within satellite networks. That is why mm-wave bands in nearest future will turn out to be the most requested in 5G and satellite communications.

World Radiocommunication Conference 2019 (WRC-19) allocated of additional mm-wave frequency bands 24.25–27.5 GHz, 37–43.5 GHz, and 66–71 GHz for 5G

terrestrial networks on a global basis. In a series of countries and regions, frequency bands of 45.5–47 GHz and 47.2-48.2 GHz received complimented allocation to terrestrial segment of IMT. This decision WRC-19 will be allowed to use some part of mm-wave bands on spectrum sharing basis for 5G satellite and 5G terrestrial network segments.

**Table 3** shown the basic frequency bands allocated to fixed and mobile satellite services, sited within the band from 10.7 to 275 GHz, designed for satellite networks and satisfied the needs for 5G channel bandwidths [7].

The analysis of spectrum bands within 12.5–86 GHz has revealed the availability of frequency bands with total bandwidth equals 17.75 GHz in up-link (UL) bands and within 10.7–76 GHz – the availability of frequency bands with total bandwidth equals 20 GHz in down-link (DL) bands for satellite networks.

In order to ensure the provision of services in the field of mass deployment of IoT devices in 5G satellite segment, it was suggested that part of S-band should utilize as a potential option with 30 MHz bandwidth [8]:


The connection between satellite 5G base station gNB and feeder link of satellite network can be performed in one of the fixed satellite service bands.

Furthermore, the study of most popular frequency bands, namely Ka-band (28 GHz) and Q/V-bands (37–53 GHz), has exposed the following features which are to be considered while elaborating the solutions for 5G.

While considering the use of Ka-band for 5G satellite segment, one should bear in mind that:


While considering the use of Q/V-bands (37-53 GHz) for 5G satellite network, one should bear in mind that:


Thus, 5G satellite segment can be constructed as the multiband one, as well as 5G terrestrial segment, which was divided into frequency bands lower 6 GHz (FR1) and higher 6 GHz (FR2) also.

**89**

38913 [4].

Total of bandwidth

**Table 3.**

systems.

*Prospects of 5G Satellite Networks Development DOI: http://dx.doi.org/10.5772/intechopen.90943*

> **Bandwidth (GHz)**

**Frequency range (GHz)**

**4. Satellite segment architecture for 5G networks**

*Frequency bands allocated to fixed and mobile satellite services.*

252.0–275.0 23.0 232.0-240.0 8.0

**57.75** Total of

bandwidth

services, that is tolerant of signal delays.

lites between 70°N and 70°S;

ing from 10 up to 12 satellites.

up to 100 satellites.

ment, shown in **Table 4** [4].

The main standardization body – 3GPP responsible for technical specifications on 5G equipment and 5G infrastructure conducted first studies regarding 5G satellite segment use, while elaborating Release 14 within Technical report 3GPP TR

**Up-link Down-link Intersatellite link**

12.5–13.25 0.75 10.7–11.7 1.0 22.55-23.55 1.0 13.75–14.8 1.0 17.7–21.2 3.5 25.25-27.5 2.25 27.5–31.0 3.5 37.0–42.5 5.5 59.0-66.0 7.0 42.5–47.0 4.5 66.0-76.0 10.0 66.0-71.0 5.0 48.2–50.2 2.0 123.0-130.0 7.0 116.0-123.0 7.0 50.4–51.4 1.0 158.5-164.0 5.5 130.0-134.0 4.0 81.0–86.0 5.0 167.0-174.5 7.5 174.5-182.0 7.5 209.0–226.0 17.0 191.8-200.0 8.2 185.0-190.0 5.0

**Bandwidth (GHz)**

**Frequency range (GHz)**

**56.2** Total of

bandwidth

**Bandwidth (GHz)**

**38.75**

**Frequency range (GHz)**

5G satellite options, presented by 3GPP related to the deployment of 5G satellite segment, are designed for 5G services delivery in areas, where their provision by 5G terrestrial segment is impeded as well as for the services supported by satellite

According to Report [4], 5G satellite segment is to complement 5G services, which delivering especially on road, rail and waterways as well as in rural regions, where access to 5G terrestrial segment is unavailable. 5G services supported via 5G satellite segment go beyond data and voice communications, providing connection with IoT devices and M2M, access to broadcasting services and a number of other

Partnership project 3GPP has come up with three options in respect of deploy-

• Geostationary satellites (GEO), located at an altitude of 35,786 km, providing full coverage of the Earth by a constellation ranging from one up to three satel-

• Medium Earth orbit (MEO), located at an altitude of 8000–20,000 km over the surface of the Earth, providing full coverage of the Earth by satellites rang-

• Low Earth Orbits (LEO) at an altitude of 500–2000 km above the Earth secures the continuity of coverage by satellite network with satellites ranging from 50

The satellite orbits, shown in **Table 4** and in **Figure 1** enable using:

*Prospects of 5G Satellite Networks Development DOI: http://dx.doi.org/10.5772/intechopen.90943*


#### **Table 3.**

*Moving Broadband Mobile Communications Forward - Intelligent Technologies for 5G…*

and satisfied the needs for 5G channel bandwidths [7].

equals 20 GHz in down-link (DL) bands for satellite networks.

• uplink (IoT device–satellite) in band: 1980–2010 MHz;

are to be considered while elaborating the solutions for 5G.

• downlink (satellite–IoT device) in band: 2170–2200 MHz.

network can be performed in one of the fixed satellite service bands.

utilize as a potential option with 30 MHz bandwidth [8]:

network segments.

in mind that:

WRC-19;

trial networks use.

one should bear in mind that:

in Release 17.

and higher 6 GHz (FR2) also.

lines of satellite network;

trial networks on a global basis by WRC-19;

terrestrial networks on a global basis. In a series of countries and regions, frequency bands of 45.5–47 GHz and 47.2-48.2 GHz received complimented allocation to terrestrial segment of IMT. This decision WRC-19 will be allowed to use some part of mm-wave bands on spectrum sharing basis for 5G satellite and 5G terrestrial

**Table 3** shown the basic frequency bands allocated to fixed and mobile satellite services, sited within the band from 10.7 to 275 GHz, designed for satellite networks

The analysis of spectrum bands within 12.5–86 GHz has revealed the availability of frequency bands with total bandwidth equals 17.75 GHz in up-link (UL) bands and within 10.7–76 GHz – the availability of frequency bands with total bandwidth

In order to ensure the provision of services in the field of mass deployment of IoT devices in 5G satellite segment, it was suggested that part of S-band should

The connection between satellite 5G base station gNB and feeder link of satellite

While considering the use of Ka-band for 5G satellite segment, one should bear

• Ka-band is a traditional satellite band, enhancing access for satellite networks;

• a part of this band has allocated for 5G terrestrial networks on a global basis by

• a few national administrations are reviewing this band in terms of 5G terres-

While considering the use of Q/V-bands (37-53 GHz) for 5G satellite network,

• V-band has not been used yet for satellite applications, in particular, for feeder

• a part of V-band has been added into bands which has allocated for 5G terres-

requirements attached to satellite as well as terrestrial segment of 5G in V-band

Thus, 5G satellite segment can be constructed as the multiband one, as well as 5G terrestrial segment, which was divided into frequency bands lower 6 GHz (FR1)

• 3GPP accelerates common efforts on joint researches as well as study of

Furthermore, the study of most popular frequency bands, namely Ka-band (28 GHz) and Q/V-bands (37–53 GHz), has exposed the following features which

**88**

*Frequency bands allocated to fixed and mobile satellite services.*

### **4. Satellite segment architecture for 5G networks**

The main standardization body – 3GPP responsible for technical specifications on 5G equipment and 5G infrastructure conducted first studies regarding 5G satellite segment use, while elaborating Release 14 within Technical report 3GPP TR 38913 [4].

5G satellite options, presented by 3GPP related to the deployment of 5G satellite segment, are designed for 5G services delivery in areas, where their provision by 5G terrestrial segment is impeded as well as for the services supported by satellite systems.

According to Report [4], 5G satellite segment is to complement 5G services, which delivering especially on road, rail and waterways as well as in rural regions, where access to 5G terrestrial segment is unavailable. 5G services supported via 5G satellite segment go beyond data and voice communications, providing connection with IoT devices and M2M, access to broadcasting services and a number of other services, that is tolerant of signal delays.

Partnership project 3GPP has come up with three options in respect of deployment, shown in **Table 4** [4].

The satellite orbits, shown in **Table 4** and in **Figure 1** enable using:



#### **Table 4.**

*Satellites and frequency band options for 5G deployment.*

#### **Figure 1.** *Typical earth orbit of communication satellite.*

The frequency bands, specified in **Table 4**, are applicable solely to a part of satellite bands (**Figure 1**), whereas modern satellite networks are deployed in broad spectrum of frequency bands, including L-band (1–2 GHz), S-band (2–4 GHz), C-band (3.4–6.725 GHz), Ku-band (10.7–14.8 GHz), Ka-band (17.3–21.2 GHz, 27.0–31.0 GHz), Q/V-bands (37.5–43.5 GHz, 47.2–50.2 GHz and 50.4–51.4 GHz), and higher.

The system architecture of 5G satellite segment is being constructed based on the use cases, mentioned in Section 1 of this chapter and two satellite technologies:


**91**

**Figure 2.**

*Prospects of 5G Satellite Networks Development DOI: http://dx.doi.org/10.5772/intechopen.90943*

tion type has shown in **Figures 2** and **3**.

frequency but preserve 5G waveform.

as a space link based on bent-pipe technology.

technology has shown in **Figure 5**.

*Signals relay architecture for 5G NR radio interface.*

base station equipment on the board of a satellite.

during propagation, network architecture for 5G satellite segment.

gNB-CU and one or more distributed modules gNB-DU(s) [9].

option implies signal reception from user devices, its regenerations, including modulation and demodulation, encryption and decryption of these signals. The architecture on-board processing also provides for the partial allocation of

In December 2017, 3GPP in scope of work on Release 16 was published Report on using satellite access in 5G [3]. The Report submitted new business cases of 5G satellite segment utilization, including Internet of Things alongside with the requirements for performance of cross-border connections and the key characteristics for satellite segment of 5G: types of orbits, coverage area, and signal delays

In accordance of proposed solutions, 5G satellite segment is inculcated into the integrated radio access network (5G RAN), which will be used satellite infrastructure and 5G core network (5G Core). 5G core can be linked up with the other generation RANs, in particular, 4G RAN, apart from satellite segment for 5G.

System architecture of 5G satellite segment, which is to be set up in accordance with the technology of bent-pipe (with transparent satellite transponders) when signal use solely to amplification and signal conditioning on retention of a modula-

As one can see in **Figures 2** and **3**, bent-pipe architecture refers to the architecture where the satellite transponders are transparent: only amplify and change

One of the important features of 5G radio access network design is that gNB base stations have a distributed architecture (**Figure 4**) and consist of a central module

The gNB-CU and gNB-DU modules are connected by a logical interface F1. The distributed module gNB-DU supports one or more cells and can only be attached to one central module gNB-CU. This architecture of the gNB base station allows to implement the concept of building an integrated 5G radio access network by placing the gNB-CU and gNB-DU modules at earth stations and realization of F1-interface

System architecture of 5G satellite segment when gNB-CU and gNB-DU modules connected each other through F1-interface by satellite links for on bent-pipe

Next options of bent-pipe architecture of 5G satellite segment has used for retranslation NG1 and NG2 interfaces, which connecting 5G base stations gNBs to

In case where 5G user device (UE) has opportunity to use satellite modem with non-3GPP radio interface for bent-pipe architecture of 5G satellite segment, the architecture option of such segment could design as shown in **Figure 7**. 5G satellite segment architecture shall support different configurations where the radio access network is either a satellite NG-RAN or a non-3GPP satellite access network, or both. **Figure 8** shows the 5G satellite segment system architecture implemented on the basis of on-board signal processing technology (with partial deployment of base

5G core. This architecture of 5G satellite segment is shown in **Figure 6**.

*Moving Broadband Mobile Communications Forward - Intelligent Technologies for 5G…*

Carrier frequency Around 1.5 or 2 GHz

UE mobility Fixed, portable,

*Satellites and frequency band options for 5G deployment.*

Typical satellite system positioning in the 5G architecture

**Technical parameters Option 1 Option 2 Option 3**

Duplexing FDD FDD FDD

System bandwidth (DL + UL) Up to 2 × 10 MHz Up to 2 × 250 MHz Up to 2 × 1000 MHz Satellite orbit GEO, LEO LEO, MEO, GEO LEO, MEO, GEO UE distribution 100% out-of-doors 100% out-of-doors 100% out-of-doors

mobile

Around 20 GHz for DL Around 30 GHz for UL

> on-board processing

Access network Backhaul network Backhaul network

Fixed, portable, mobile

Around 40 or 50 GHz

Bent-pipe, on-board processing

> Fixed, portable, mobile

for both DL and UL

Satellite architecture Bent-pipe Bent-pipe,

**90**

**Figure 1.**

**Table 4.**

*Typical earth orbit of communication satellite.*

50.4–51.4 GHz), and higher.

The frequency bands, specified in **Table 4**, are applicable solely to a part of satellite bands (**Figure 1**), whereas modern satellite networks are deployed in broad spectrum of frequency bands, including L-band (1–2 GHz), S-band (2–4 GHz), C-band (3.4–6.725 GHz), Ku-band (10.7–14.8 GHz), Ka-band (17.3–21.2 GHz, 27.0–31.0 GHz), Q/V-bands (37.5–43.5 GHz, 47.2–50.2 GHz and

The system architecture of 5G satellite segment is being constructed based on the use cases, mentioned in Section 1 of this chapter and two satellite technologies:

1.The architecture based on the technology of bent-pipe (with invisible satellite transponders without On-Board Processing) – this option envisages signal reception from user devices, its amplification, its transfer on other frequency

2.The architecture based on the technology of On-Board Processing (with satellite transponders, complimented with data processing on board) – this

and relaying in the direction of satellite gateway.

option implies signal reception from user devices, its regenerations, including modulation and demodulation, encryption and decryption of these signals. The architecture on-board processing also provides for the partial allocation of base station equipment on the board of a satellite.

In December 2017, 3GPP in scope of work on Release 16 was published Report on using satellite access in 5G [3]. The Report submitted new business cases of 5G satellite segment utilization, including Internet of Things alongside with the requirements for performance of cross-border connections and the key characteristics for satellite segment of 5G: types of orbits, coverage area, and signal delays during propagation, network architecture for 5G satellite segment.

In accordance of proposed solutions, 5G satellite segment is inculcated into the integrated radio access network (5G RAN), which will be used satellite infrastructure and 5G core network (5G Core). 5G core can be linked up with the other generation RANs, in particular, 4G RAN, apart from satellite segment for 5G.

System architecture of 5G satellite segment, which is to be set up in accordance with the technology of bent-pipe (with transparent satellite transponders) when signal use solely to amplification and signal conditioning on retention of a modulation type has shown in **Figures 2** and **3**.

As one can see in **Figures 2** and **3**, bent-pipe architecture refers to the architecture where the satellite transponders are transparent: only amplify and change frequency but preserve 5G waveform.

One of the important features of 5G radio access network design is that gNB base stations have a distributed architecture (**Figure 4**) and consist of a central module gNB-CU and one or more distributed modules gNB-DU(s) [9].

The gNB-CU and gNB-DU modules are connected by a logical interface F1. The distributed module gNB-DU supports one or more cells and can only be attached to one central module gNB-CU. This architecture of the gNB base station allows to implement the concept of building an integrated 5G radio access network by placing the gNB-CU and gNB-DU modules at earth stations and realization of F1-interface as a space link based on bent-pipe technology.

System architecture of 5G satellite segment when gNB-CU and gNB-DU modules connected each other through F1-interface by satellite links for on bent-pipe technology has shown in **Figure 5**.

Next options of bent-pipe architecture of 5G satellite segment has used for retranslation NG1 and NG2 interfaces, which connecting 5G base stations gNBs to 5G core. This architecture of 5G satellite segment is shown in **Figure 6**.

In case where 5G user device (UE) has opportunity to use satellite modem with non-3GPP radio interface for bent-pipe architecture of 5G satellite segment, the architecture option of such segment could design as shown in **Figure 7**. 5G satellite segment architecture shall support different configurations where the radio access network is either a satellite NG-RAN or a non-3GPP satellite access network, or both.

**Figure 8** shows the 5G satellite segment system architecture implemented on the basis of on-board signal processing technology (with partial deployment of base

**Figure 2.** *Signals relay architecture for 5G NR radio interface.*

#### **Figure 3.**

*Relaying architecture based on 5G user device with UE relay.*

#### **Figure 4.**

*Architecture 5G base station gNB.*

**Figure 5.**

*Architecture 5G base station gNB with F1-satellite interface.*

#### **Figure 6.**

*Signals relay architecture for NG1 and NG2 interfaces.*

station processing equipment in satellite). As on-board signal processing payload uses distributed module gNB-DU of 5G base station and as satellite link utilizes 5G NR radio interface.

In accordance design principle of base stations gNBs, some distributed modules gNB-DUs can connect to only one central module gNB-CU. That makes easier 5G coverage of big areas. The solution for 5G satellite segment architecture on regenerative payload enabled NR-RAN with intersatellite links (ISL) for regional or global coverage shown in **Figure 9** [10]. Intersatellite links provide logical F1-interface between distributed modules gNB-DUs, which use Satellite Radio Interface (SRI) over F1 as a transport link between remote radio unit with gNB-CU and satellites.

Second solution for 5G satellite segment architecture (**Figure 10**) has used 5G base station gNB on satellite (as regenerative payload) enabled NR-RAN with ISLs

**93**

**Figure 9.**

*global coverage.*

*Prospects of 5G Satellite Networks Development DOI: http://dx.doi.org/10.5772/intechopen.90943*

connect these gNBs with 5G core network.

*Signals relay architecture for non-3GPP interface.*

*5G satellite segment architecture based on the on-board processing technology [4].*

*5G satellite segment architecture on regenerative satellite payloads enabled NR-RAN, with ISL for regional or* 

**Figure 7.**

**Figure 8.**

that provide SRI application over Xn-C and Xn-U interfaces. In this case between remote radio units and satellite gNBs will be used, and 5G standard NG-interfaces

Mobile devices of 5G satellite segment architecture (**Figures 2**–**10**) will be presented on the market by user terminals as well as the other wearable devices, installed in cars, ships, planes, etc. Nowadays the potential of wearable satellite user that provide SRI application over Xn-C and Xn-U interfaces. In this case between remote radio units and satellite gNBs will be used, and 5G standard NG-interfaces connect these gNBs with 5G core network.

Mobile devices of 5G satellite segment architecture (**Figures 2**–**10**) will be presented on the market by user terminals as well as the other wearable devices, installed in cars, ships, planes, etc. Nowadays the potential of wearable satellite user

**Figure 8.**

*Moving Broadband Mobile Communications Forward - Intelligent Technologies for 5G…*

station processing equipment in satellite). As on-board signal processing payload uses distributed module gNB-DU of 5G base station and as satellite link utilizes 5G

In accordance design principle of base stations gNBs, some distributed modules gNB-DUs can connect to only one central module gNB-CU. That makes easier 5G coverage of big areas. The solution for 5G satellite segment architecture on regenerative payload enabled NR-RAN with intersatellite links (ISL) for regional or global coverage shown in **Figure 9** [10]. Intersatellite links provide logical F1-interface between distributed modules gNB-DUs, which use Satellite Radio Interface (SRI) over F1 as a transport link between remote radio unit with gNB-CU and satellites. Second solution for 5G satellite segment architecture (**Figure 10**) has used 5G base station gNB on satellite (as regenerative payload) enabled NR-RAN with ISLs

**92**

NR radio interface.

**Figure 5.**

**Figure 4.**

*Architecture 5G base station gNB.*

**Figure 3.**

**Figure 6.**

*Architecture 5G base station gNB with F1-satellite interface.*

*Relaying architecture based on 5G user device with UE relay.*

*Signals relay architecture for NG1 and NG2 interfaces.*

*5G satellite segment architecture based on the on-board processing technology [4].*

#### **Figure 9.**

*5G satellite segment architecture on regenerative satellite payloads enabled NR-RAN, with ISL for regional or global coverage.*

*Moving Broadband Mobile Communications Forward - Intelligent Technologies for 5G…*

**Figure 10.**

*5GS with regenerative satellite enabled NR-RAN, with ISL and multiple 5G Core connectivity.*

terminals is limited to L- and S-frequency bands. However, the studies regarding the potential functioning of 5G satellite user terminals within Ku and mm-wave bands are still ongoing.
