WO2022077246A1

WO2022077246A1 - System and methods for identifying edge application server

Info

Publication number: WO2022077246A1
Application number: PCT/CN2020/120753
Authority: WO
Inventors: Xiaojian YAN; Jinguo Zhu
Original assignee: Zte Corporation
Priority date: 2020-10-14
Filing date: 2020-10-14
Publication date: 2022-04-21
Also published as: CN116458137A

Abstract

A method for wireless communications comprising: in response to a first network node receiving a session establishment request from a wireless device, providing to the wireless device, by the first network node, an IP address of a second network node included in one or more second network nodes, wherein the second network node is configured as a DNS resolver for serving one or more DNS queries from the wireless device; and sending, by the first network node to the second network node, a mapping between domain names and a subset of network access identifiers included in a list of network access identifiers for accessing data networks, wherein the subset of network access identifiers is selected according to a current location of the wireless device.

Description

SYSTEM AND METHODS FOR IDENTIFYING EDGE APPLICATION SERVER

TECHNICAL FIELD

This patent document is directed generally to wireless communications.

BACKGROUND

In Edge Computing deployments, one application service might be served by multiple Edge Application Servers typically deployed in different sites. The multiple EAS (Edge Application Server) instances hosting the same content or service may use a single IP address (e.g., an anycast address) or different IP addresses. Before an application/UE starts to connect to the service, it is important for the application/UE to identify (or, “discover” ) the IP address of one suitable Edge Application Server (e.g., the closest one) , so that the traffic can be locally routed to the Edge Application Server via UL CL/BP mechanisms, with a goal of optimizing transmission parameters such as service latency, traffic routing path, and user service experience associated with the discovered EAS. In the event the UE moves away, the Edge Application Server may no longer be optimized. Accordingly, a new EAS instance (optimized for the transmission parameters) replaces the old EAS for serving the application/UE.

SUMMARY

In one exemplary embodiment, a method for wireless communication includes in response to a first network node receiving a session establishment request from a wireless device, providing to the wireless device, by the first network node, an IP address of a second network node included in one or more second network nodes, wherein the second network node is configured as a DNS resolver for serving one or more DNS queries from the wireless device; and sending, by the first network node to the second network node, a mapping between domain names and a subset of network access identifiers included in a list of network access identifiers for accessing data networks, wherein the subset of network access identifiers is selected according to a current location of the wireless device.

In another exemplary embodiment, a method for wireless communication includes receiving, at a domain name service (DNS) resolver node, a mapping between domain names and a set of network access identifiers for accessing data networks; upon receiving a DNS query comprising a requested domain name originating from a wireless device, the DNS resolver node determining a network access identifier based on the mapping information and the requested domain name; and in response to receiving from a DNS server an IP address of an application server configured to serve a current location of the wireless device, sending, by the DNS resolver node, the IP address of the application server to the wireless device.

In yet another aspect, a wireless communication apparatus that implements an above-described method is disclosed. The apparatus may contain a processor and a transceiver for signal reception and transmission.

In another example aspect, a computer readable medium storing code that, when executed, causes a processor to implement an above-described method is disclosed.

These, and other, aspects are further described in the present document.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an overview of an architecture for identifying an EAS.

FIG. 2 is a signaling process for identifying an EAS, in accordance with an example embodiment.

FIG. 3 is a signaling process for handling DNS queries using a C-DNS network server, in accordance with an example embodiment.

FIG. 4 is a signaling process for handling DNS queries using a L-DNS network server, in accordance with an example embodiment.

FIG. 5 shows an example of a wireless communication system where techniques in accordance with one or more embodiments of the present technology can be applied.

FIG. 6 is a block diagram representation of a portion of a hardware platform.

FIG. 7 illustrates a flowchart of an example method associated with identifying an EAS.

FIG. 8 illustrates a flowchart of an example method associated with identifying an EAS.

DETAILED DESCRIPTION

Section headings are used in the present document only for ease of understanding and do not limit scope of the embodiments to the section in which they are described. Furthermore, while embodiments are described with reference to 5G examples, the disclosed techniques may be applied to wireless systems that use protocols other than 5G or 3GPP protocols.

The development of the new generation of wireless communication-5G New Radio (NR) communication-is a part of a continuous mobile broadband evolution process to meet the requirements of increasing network demand. NR will provide greater throughput to allow more users connected at the same time. Other aspects, such as energy consumption, device cost, spectral efficiency, and latency are also important to meeting the needs of various communication scenarios.

Overview

The structure may of a 5G wireless network can include a 5G core network (5GC or 5G core) and a 5G access network. The 5G core network may include network elements relating to an access and mobility management unit (AMF) , a user plane function (UPF) , and a 5G access network that may include a network element 5G enhanced eNB base station (ng-eNB) or a 5G base station (gNB) . The interface between the network element of the core network and the network element of the access network may include an NG interface, and the interface between the network elements of the access network may include an Xn interface. A RAN node can be a gNB (5G base station) providing New Radio (NR) user plane and control plane services. As another example, a RAN node can be an enhanced 4G eNodeB that connects to the 5G Core network via the NG interfaces but still uses 4G LTE air interface (s) to communicate with the 5G UE/wireless device.

Example Embodiments

Embodiments disclosed herein are directed at DNS-based EAS discovery. For example, the disclosed embodiments can be applicable to identify information about an EAS server from a collection of distributed EAS servers in response to a DNS query from a UE. For example, the collection of EAS servers distributed in a geographical area can be configured to serve UE’s corresponding to the geographical area. In some embodiments, a DNS resolver (termed “LDNSR” herein) is used to resolve DNS queries by interacting with the session management function (SMF) of the 5G wireless system. Advantageously, the disclosed technology reduces computational load on the SMF by relying less on the SMF and rather using the LDSNR for handling DNS queries. Accordingly, in the examples in this document, improved SMF and LDSNR functionalities are discussed.

In some implementations, DNS queries from wireless devices are processed by a C-DNS server or a L-DNS server (which is distinct or different from the LDNSR) . As a result, interactions with the SMF for each DNS query to determine the L-DNS server IP or the edns-client-subnet (ECS) option (associated with the C-DNS server IP) increases the computational load on the SMF. To avoid the load increase, or otherwise eliminate interactions with the SMF associated with identifying an appropriate C-DNS or L-DNS server, embodiments discussed herein are directed at methods of pushing information from the SMF to the LDNSR so that the LDNSR can determine the ECS option or L-DNS address, upon the LDNSR receiving an uplink DNS query from the UE. The LDNSR is configured with the mapping between the data network access identifier (DNAI) and the corresponding edns-client-subnet (ECS) option or L-DNS address. This mapping information is on a per node basis so that it can be provided to the LDNSR before the PDU session establishment. During PDU session establishment or UE mobility, the SMF provides the application description (e.g., the fully qualified domain name (FQDN) ) and the DNAI available in the UE location to the LDNSR. After the LDNSR receives a DNS query, the LDNSR can determine the ECS option or L-DNS address (e.g., related to the UE’s location) and the application description (requested FQDN) , without interacting with the SMF.

FIG. 1 shows an overview of an architecture for identifying EAS using LDNSR. This architecture includes the following components or modules:

1) UE, User Equipment 118. Before starting to connect to the service, the UE identifies (or “discovers” ) the IP address of one suitable EAS (e.g., the closest one) , so that the traffic can be locally routed to the Edge Application Server via UL CL/BP mechanisms, with a goal of optimizing transmission parameters such as service latency, traffic routing path, and user service experience associated with the discovered EAS. In the event the UE moves away, the Edge Application Server may no longer be optimized. Accordingly, a new EAS instance (optimized for the transmission parameters) replaces the old EAS for serving the application/UE.

2) LDNSR, Local DNS Resolver 106. LDNSR is an enhanced DNS Forwarder. LDNSR performs the role of a DNS Resolver and interacts with the SMF. The LDNSR is connected to the C-DNS and the L-DNS servers. The LDNSR is configured as a DNS server to the UE during PDU session establishment by SMF via protocol configuration options (PCO) . In some implementations, the LDSNR can be part of PSA UPF of the 5G core network. In some implementations, the LDSNR can be a standalone 5G core network functionality. Thus, in essence, the LDNSR is a special /dedicated local DNS resolver that is part of the 5G core network.

When the UE sends a DNS query to the LDSNR, the LDNSR interacts with the SMF to determine configuration parameters associated with the FQDN in the DNS query. This interaction is before establishing a PDU session. Embodiments disclosed herein allow for more than one manner of determining In some embodiments, the LDSNR can determine configuration parameters based on more than one option provided by the SMF. The LDNSR can choose configuration parameters associated with any of option 1, option 2, option 3, etc. For example, the configuration parameters (according to option 1 in FIG. 1) may include the mapping between the DNAI and the corresponding edns-client-subnet (ECS) option (s) . Alternately, the configuration parameters (according to option 2 in FIG. 1) may include the mapping between the DNAI and the corresponding L-DNS address. In some embodiments, the configuration parameters can be locally configured at the LDNSR before each PDU session establishment.

In some implementations (shown as option 1 in FIG. 1) , the LDNSR is locally configured or per node configured by the SMF with the mapping between the DNAI and the corresponding ECS option, before the PDU session establishment. In some implementations (shown as option 2 in FIG. 1) , the LDNSR is locally configured or per node configured by the SMF with the mapping between the DNAI and the corresponding L-DNS address, before the PDU session establishment. In some embodiments, there is one LDNSR communicably coupled to the SMF for implementing the methods discussed herein. In some embodiments, more than one LDNSRs can be communicably coupled to the SMF for implementing the methods discussed herein. In some embodiments, e.g., as shown in FIG. 1, the LDNSR and the L-DNS server are distinct or different from each other.

3) SMF, Session Management Function 104. This function is part of the 5G core network and includes the following functionalities: session establishment, modification and release, UE IP address allocation and management (including optional authorization functions) , selection and control of UP function, downlink data notification, etc. The SMF configures the UE with the address of LDNSR as the DNS server during PDU session establishment via protocol configuration options (PCO) to request various network parameters, and dynamically (upon LDNSR notifications) inserts UL CL/BP and local PSA. (Because the insertion is on-the-fly or dynamic, the UL CL/BP and local PSA blocks are shown with dotted lines in FIG. 1. )

4) C-DNS, Centralized DNS server 102. C-DNS server is configured for resolving the UE DNS queries into a suitable Edge Application Server (EAS) IP address. It is typically deployed at a central location by a MNO or a third party.

5) L-DNS server, Local DNS server 110. L-DNS server may be locally deployed within an edge hosting environment, and responsible for resolving the UE DNS queries into a suitable EAS IP address within the Local data network (DN) .

6) PSA, PDU Session Anchor (shown as local PSA 114 and remote PSA 108) . For example, in FIG. 1, a UE might be served by the remote PSA 118. Due to UE mobility, i.e., when the UE moves outside of a tracking area, the network may need to relocate the UPF acting as UL /CL and establish a different PSA for access to the local DN. Thus, when the SMF becomes aware of the address of the closest EAS (e.g., EAS 116) for the UE, the SMF selects a new UPF as the PSA. In some implementations, a given UPF can support both the UL CL and the PSA functionalities. As a result, the UE becomes associated with local PSA 114, which is topologically close to EAS 116. (This is to ensure the selected local PSA and EAS are corresponding to the same DNAI. ) The SMF sends the EAS IP address to the UL CL/BP (e.g., UL CL /BP 112) as the destination IP address within the traffic filter. Subsequently, when the UE sends traffic to EAS 116, the ULCL/BP diverts the traffic to EAS 116 via the local PSA 114 since the traffic matches the traffic filter provided by the SMF.

7) UL CL/BP, uplink classifier/branch point 112. The UL CL/BP is a functionality supported by an UPF for diverting (locally) some traffic matching traffic filters provided by the SMF.

8) EAS, Edge Application Server 116. EAS is a server hosting applications that can be accessed by a UE. Typically, the EAS is located close to the UE (or, serving a current location of the UE) to improve network latency, performance of applications, and efficiency of delivering content. In some implementations, multiple EASs can be deployed to cover a large geographical area. Embodiments of the present disclosure are directed at determining the IP address of an EAS corresponding to a current location of the UE. For example, at a location A, EAS 1 may be the optimized (e.g., closes) EAS. When the UE moves to a location B, EAS 2 may be the optimized WAS.

Example Embodiment 1

FIG. 2 is a signaling process for identifying an EAS, in accordance with an example embodiment. Steps of the signaling process are discussed below.

Prior to establishing a communication session (i.e., prior to step 0) , the SMF sends to the LDNSR, a first mapping information between DNAIs (alternately referred herein as network access identifiers) and IP addresses of DNS servers configured to process DNS queries from wireless devices. Examples of DNS servers can be the C-DNS server (discussed in option 1) or the L-DNS server (discussed in option 2) . If multiple LDNSRs are deployed, the SMF sends the first mapping information (e.g., one or more DNAIs and IP address (es) of one or more C-DNS servers or L-DNS servers) to each of the LDNSRs. The C-DNS servers and/or the L-DNS servers can be located locally or in close proximity relative to the UE’s current location. In some embodiments, the LDNSR can be a PDU session anchor user plane function (UPF) . In some embodiments, the LDNSR can be a standalone 5G core network function.

In some implementations, the application function (AF) can send one or more FQDNs and one or more DNAI lists to the SMF. For example, if the AF is QQ server, FQDN is tencent. com, the DNAI list can include DNAI 1 (identifying City A) and DNAI 2 (identifying City B) . This indicated that City A and City B have their local QQ server. In some implementations, multiple AFs can provide FQDNs and DNAI lists. For example, the SMF can receive list 1 (including FQDN1, DNAI1) from QQ server, list2 (including FQDN2, DNAI2) from Baidu server, and list3 (including FQDN3, DNAI3) from Google server. Each list can include one or more FQDNs and one or more DNAIs. In some embodiments, the SMF can locally configure the lists.

Generally, a FQDN is the complete domain name for a specific computer, or host, on the internet. The FQDN can specify the exact location of a host within a tree hierarchy of the Domain Name System (DNS) . The FQDN can include two parts: the hostname and the domain name. For example, an FQDN for a hypothetical mail server might be mail. myuniversity. edu. As another example, “www. techterms. com. ” is an FQDN since it contains a hostname ( “www” ) and a domain name ( “techterms. com” ) , followed by a trailing period (. ) . However, the name “techterms. com” is not a fully qualified domain name because neither does it include a hostname nor does it end with a period.

Step 0: The UE sends a request to establish a PDU session with PSA1. PSA1 can forward the session establishment request to the SMF. The session establishment request from the UE can include information regarding the current location of the UE. In some implementations, the UE can provide the SMF the current location of the UE in other types of messages or notifications. In response to the PDU session establishment request, the SMF sends the UE the IP address of LDNSR as the DNS server via PCO, and dynamically (upon LDNSR notifications) inserts ULCL/BP and local PSA. A PDU session establishment can be requested by the UE, or alternately, a PDU session can be initiated by the 5G network. Further, a PDU session establishment can be an “Initial Request, ” “Existing Session, ” or a “PDU session Handover” because of mobility of the UE. From the perspective of the UE, the LDNSR is a normal DNS resolver, and hence, each DNS query over the PDU session will be sent to the LDNSR.

Based on receiving the session establishment request from the UE, the SMF determines a second mapping between domain names (or, FQDNs) and a subset of DNAI lists. The subset of DNAI lists are network access identifiers associated with a current location of the UE. The SMF can send the second mapping to the LDNSR. The first mapping (e.g., sent to the SMF before a session establishment) and the second mapping (e.g., sent to the SMF based on the UE’s current location) can be considered as configuration parameters.

Step 1. A DMS query is triggered at the UE.

Step 2. The UE sends the DNS query including a requested domain name (or, more formally, a requested fully qualified domain name (FQDN) ) . The PSA1 UPF forwards the received DNS query to the LDNSR.

Step 3. Based on the configuration parameters (e.g., the first mapping and the second mapping) received from the SMF (prior to establishing a communication session with the wireless device) for the FQDN requested in the DNS query, the LDNSR determines the following forwarding parameters:

Option 1: In this embodiment, the LDNSR transfers (or, equivalently forwards) the DNS query to a C-DNS server identified by a dedicated IP address. Further, in this embodiment, the LDSNR determines (as a parameter) the dedicated IP address to add as an ECS DNS option in the DNS query originating from the wireless device. The IP address may correspond to the Data Network Access Identifier (DNAI) associated by the SMF with the UE location and a target domain. A DNAI can be an identifier of a user plane access to one or more data networks where applications are deployed.

Option 2: In this embodiment, the LDNSR transfers (or, equivalently forwards) the DNS query to the L-DNS server. Further, in this embodiment, the LDSNR determines the IP address of the L-DNS server to whom the DNS request is to be sent. This L-DNS address may correspond to the DNAI associated by the SMF with the UE location and a target domain.

Steps 4a–4b: Option 1 --The LDNSR adds the IPv4 subnet or address or IPv6 prefix provisioned by the SMF in step 3 as ECS option (e.g., as specified in RFC 7871) and sends it to C-DNS server. The C-DNS returns the DNS response including EAS IP address.

Steps 4c–4d: Option 2 --The LDNSR sends the DNS query to the L-DNS server provisioned by the SMF and gets the DNS response including the EAS IP address.

For both steps 4a–4b (corresponding to option 1) and steps 4c–4d (corresponding to option 2) , upon receiving the DNS response, the LDNSR may notify the SMF with IP address of EAS and a selected DNAI, if certain criteria set by the SMF are matched. Examples of criteria can include the IP address of EAS in DNS response is within the IP range (s) indicated by SMF, or the FQDN is matched. The FDQN is matched when the LDNSR determines that the requested domain name in the DNS request is same or associated with a domain name in the second mapping information received from the SMF. Then, the SMF decides whether to trigger the insertion of the ULCL/Local PSA.

Step 5a: The SMF performs UL CL/Local PSA selection and set up. The DNAI and UL CL/Local PSA is selected based on the information provided by LDNSR to ensure the selected local PSA and EAS correspond to the same DNAI. For example, the SMF selects a network node for operating as a user plane function (UPF) with respect to the current location of the wireless device and the selected network access identifier received in the notification from the LDNSR.

Step 5b: In the case of IPv6 multi-homing, the SMF notifies the UE of the availability of the new IP prefix using an IPv6 Router Advertisement message.

Step 6: The LDNSR sends the DNS response to the UE via PSA1.

Example Embodiment 2

FIG. 3 is a signaling process for handling DNS queries using a C-DNS network server, in accordance with an example embodiment (also discussed as option 1 in FIG. 2) . In this embodiment, the LDNSR is locally configured or per node configured by the SMF (before the PDU session establishment) with the mapping between the DNAI and the corresponding ECS option (e.g., the first mapping discussed in FIG. 2) . Steps of the signaling process are discussed below.

Step 0. During PDU Session Establishment procedure, the address of LDNSR is provided by SMF via PCO to UE. The PDU session is established with PSA1.

Step 1. The SMF may receive PCC rule including Traffic description (FQDN) and DNAI list. Optionally, FQDN and DNAI list are locally configured in the SMF. At PDU session establishment and during UE mobility, the SMF determines a subset of the DNAI list based on the UE location, and provides the LDNSR with the subset of DNAI list for the relevant FQDNs. For example, the SMF sends FQDN1+DNAI1 to LDNSR, later when the UE moves, the SMF sends FQDN1+DNAI2 to replace FQDN1+DNAI1. Thus, the first subset is updated as a result of mobility. In some embodiments, the UE’s current location can be associated with more than one DNAI. In those embodiments, the SMF can send the multiple DNAIs (e.g., multiple subsets of network access identifiers) to the LDSNR. The LDSNR can select an applicable DNAI from the multiple DNAIs associated with the UR’s location.

Step 2. The SMF may subscribe to the LDNSR for the notification that LDNSR receives DNS response including the EAS IP address.

Step 3. The UE sends a DNS query including the requested FQDN (i.e., the requested domain name) and/or a current location of the UE.

Step 4. The PSA1 UPF forwards the received DNS query to the LDNSR. The LDNSR selects the DNAI corresponding to the requested FQDN based on the information received in step 1 from the SMF, and determines the ECS option corresponding to the selected DNAI based on the configured mapping between the DNAI and ECS option. For example, first using the second mapping (a subset of DNAIs corresponding to the UE’s location and one or more FQDNs) and the requested FQDN in the DNS query, the LDNSR can determine a DNAI. Next, using the determined DNAI and the first mapping (one or more DNAIs and one or more IP addresses of C-DNS servers) received from the SMF, the LDNSR can determine an IP address of a C-DNS server. The C-DNS server is identified by a dedicated IP address corresponding to an edns-client-subnet (ECS) option based on the current location of the wireless device.

Step 5: The LDNSR adds the ECS option determined in step 4 to the DNS request (e.g., DNS query) sent to C-DNS server.

Step 6. The C-DNS returns the DNS response including EAS IP address.

Step 7. Upon receiving the DNS response, the LDNSR notifies SMF with EAS IP address and the DNAI and N6 routing information (e.g., routing information used for selecting a port to access the requested domain name) . For example, the DNAI can be a network access identifier corresponding to a match between a requested domain name included in the DNS query and the domain names included in the second mapping.

Step 8a. The SMF decides to trigger the insertion of the ULCL/Local PSA. The SMF selects the local PSA based on the information received from the LDNSR to ensure the selected local PSA and EAS are corresponding to same DNAI, inserts the ULCL/BP and establish the user plane towards the local PSA, and sends the EAS IP address to the ULCL/BP for traffic detection.

Step 8b. In the case of IPv6 multi-homing, the SMF notifies the UE of the availability of the new IP prefix using an IPv6 Router Advertisement message.

Step 9. The LDNSR sends DNS response to UE via PSA1.

Example Embodiment 3

FIG. 4 is a signaling process for handling DNS queries using a L-DNS network server, in accordance with an example embodiment (also discussed as option 2 in FIG. 2) . In this embodiment, the LDNSR is locally configured or per node configured by the SMF (before the PDU session establishment) with the mapping between the DNAI and the corresponding L-DNS address (e.g., the first mapping discussed in FIG. 2) . Steps of the signaling process are discussed below.

Step 1. The SMF may receive PCC rule including Traffic description (FQDN) and DNAI list. Optionally, FQDN and DNAI list are locally configured in the SMF. At PDU session establishment and during UE mobility, the SMF determines a subset of the DNAI list based on the UE location, and provides the LDNSR with the subset of DNAI list for the relevant FQDNs.

Step 3. The UE sends a DNS query including the requested FQDN and/or a current location of the UE.

Step 4. The PSA1 UPF forwards the received DNS query to the LDNSR. The LDNSR selects the DNAI corresponding to the requested FQDN based on the information received in step 1 from the SMF, and determines the L-DNS server IP address corresponding to the selected DNAI based on the configured mapping between the DNAI and L-DNS address. For example, first using the second mapping (a subset of DNAIs corresponding to the UE’s location and one or more FQDNs) and the requested FQDN, the LDNSR can determine a DNAI. Next, using the determined DNAI and the first mapping (including one or more DNAIs and one or more IP addresses of L-DNS servers) received from the SMF, the LDNSR can determine an IP address of a L-DNS server. In some implementations, the L-DNS server determined by the LDNSR for processing DNS queries from the wireless device can be located locally with respect to the UE or in close proximity to the UE. In some implementations, the L-DNS server determined by the LDNSR for processing DNS queries from the wireless device can be located locally with respect to the LDNSR or in close proximity to the LDNSR.

Step 5: The LDNSR sends the DNS query to the L-DNS server. The L-DNS server can be a

Step 6. The L-DNS server returns the DNS response including the EAS IP address, i.e., the IP address of the edge application server.

Step 7. Upon receiving the DNS response, the LDNSR notifies SMF with EAS IP address and the DNAI and N6 routing information (e.g., routing information used for selecting a port to access the requested domain name) .

Step 8a. The SMF decides to trigger the insertion of the ULCL/Local PSA. The SMF selects the local PSA based on the information received from the LDNSR to ensure the selected local PSA and EAS are corresponding to same DNAI, insert the ULCL/BP and establish the user plane towards the local PSA, and sends the EAS IP address to the ULCL/BP for traffic detection.

Step 9. The LDNSR sends DNS response to UE via PSA1.

Example System Implementations

LDNSR Functionalities

Example functionalities of the LDNSR (e.g., which maybe the “second network node” in FIG. 7 or the “DNS resolver node” in FIG. 8) are discussed below.

1) LDNSR is locally configured or per node configured by the SMF with the mapping between the DNAI and the corresponding ECS option or L-DNS address.

2) LDNSR receives a subset of the DNAI list and FQDN from the SMF.

3) LDNSR receives DNS query including the requested FQDN.

4) LDNSR selects the DNAI corresponding to the requested FQDN based on the information received from the SMF.

5) LDNSR determines ECS option or L-DNS address corresponding to selected DNAI based on the configured mapping between DNAI and ECS option or L-DNS address.

6) LDNSR includes the ECS option in the DNS request sent to the C-DNS server.

7) LDNSR sends DNS request to the L-DNS server.

8) LDNSR receives the DNS response from the C-DNS server or L-DNS server including the EAS IP address.

9) LDNSR notifies the SMF with the received EAS IP address and the selected DNAI.

SMF Functionalities

Example functionalities of the SMF (e.g., which maybe the “first network node” in FIG. 7 or the “core network node” in FIG. 8) are discussed below.

1) SMF receives PCC rule including Traffic description (FQDN) and DNAI list or locally configures the FQDN and DNAI list.

2) SMF determines a subset of the DNAI list based on the UE location.

3) SMF provides the LDNSR with the subset of the DNAI and the FQDN.

4) SMF receives notification from LDNSR, which includes the EAS IP address and the selected DNAI.

5) SMF selects the local PSA based on the information received from the LDNSR.

6) SMF inserts the ULCL/BP and establish the user plane towards the local PSA.

7) SMF sends the EAS IP address to the ULCL/BP for traffic detection.

FIG. 5 shows an example of a wireless communication system where techniques in accordance with one or more embodiments of the present technology can be applied. A wireless communication system 500 can include one or more base stations (BSs) 505a, 505b, one or

more wireless devices

510a, 510b, 510c, 510d, and a core network 525. A

base station

505a, 505b can provide wireless service to

wireless devices

510a, 510b, 510c, and 510d in one or more wireless sectors. In some implementations, a

base station

505a, 505b includes directional antennas to produce two or more directional beams to provide wireless coverage in different sectors.

The core network 525 can communicate with one or

more base stations

505a, 505b. The core network 525 provides connectivity with other wireless communication systems and wired communication systems. The core network may include one or more service subscription databases to store information related to the subscribed

wireless devices

510a, 510b, 510c, and 510d. A first base station 505a can provide wireless service based on a first radio access technology, whereas a second base station 505b can provide wireless service based on a second radio access technology. The

base stations

505a and 505b may be co-located or may be separately installed in the field according to the deployment scenario. The

wireless devices

510a, 510b, 510c, and 510d can support multiple different radio access technologies. In some embodiments, the

base stations

505a, 505b may be configured to implement some techniques described in the present document. The wireless devices 510a–510d may be configured to implement some techniques described in the present document.

In some implementations, a wireless communication system can include multiple networks using different wireless technologies. A dual-mode or multi-mode wireless device includes two or more wireless technologies that could be used to connect to different wireless networks.

FIG. 6 is a block diagram representation of a portion of a hardware platform. A hardware platform 605 such as a network node or a base station or a wireless device (or UE) can include processor electronics 610 such as a microprocessor that implements one or more of the techniques presented in this document. The hardware platform 605 can include transceiver electronics 615 to send and/or receive wired or wireless signals over one or more communication interfaces such as antenna 620 or a wireline interface. The hardware platform 605 can implement other communication interfaces with defined protocols for transmitting and receiving data. The hardware platform 605 can include one or more memories (not explicitly shown) configured to store information such as data and/or instructions. In some implementations, the processor electronics 610 can include at least a portion of the transceiver electronics 615. In some embodiments, at least some of the disclosed techniques, modules or functions, a central node, a distributed node, a terminal or network nodes are implemented using the hardware platform 605.

Some technical solutions are presented in a clause-based format and are preferably implemented in some embodiments.

1. A method (e.g., method 700 depicted in FIG. 7) for wireless communications comprising: in response to a first network node receiving a session establishment request from a wireless device, providing (702) to the wireless device, by the first network node, an IP address of a second network node included in one or more second network nodes, wherein the second network node is configured as a DNS resolver for serving one or more DNS queries from the wireless device; and sending (704) , by the first network node to the second network node, a mapping between domain names and a subset of network access identifiers included in a list of network access identifiers for accessing data networks, wherein the subset of network access identifiers is selected according to a current location of the wireless device.

2. The method of clause 1, wherein the mapping between the domain names and the subset of network access identifiers is a second mapping, wherein the first wireless network node is configured to send a first mapping prior to establishing a session with the wireless device, further comprising: sending, by the first network node to the one or more second network nodes, the first mapping between at least one network access identifier for accessing the data networks and an IP address of at least one local domain name service (L-DNS) server that is configured to process DNS queries from wireless devices for identifying an application server in a plurality of application servers.

3. The method of clause 1, wherein the mapping between the domain names and the subset of network access identifiers is a second mapping, wherein the first wireless network node is configured to send a first mapping prior to establishing a session with the wireless device, further comprising: sending, by the first network node to one or more second network nodes, a first mapping between at least one network access identifier for accessing the data networks and a dedicated IP address corresponding to an edns-client-subnet (ECS) option.

4. The method of clause 1, wherein the subset of network access identifiers at a first location of the wireless device is a first subset, further comprising: upon determining the wireless device moved to a different second location from a first location, selecting, at the first network node, a second subset of network access identifiers from the list of network access identifiers based on the second location of the wireless device; generating an updated second mapping using the second subset and associated domain names; and sending the updated second mapping to the second network node.

5. The method of clause 1, further comprising: receiving, from the second network node, a notification relating to a DNS response associated with a DNS query, wherein the notification relating to the DNS response includes an IP address of an application server serving a current location of the wireless device.

6. The method of clause 5, wherein the notification relating to the DNS response additionally includes a selected network access identifier corresponding to a match between a requested domain name included in the DNS query and the domain names included in the second mapping.

7. The method of clause 6, wherein the communication session is a protocol data unit (PDU) session, further comprising: receiving, at the first network node, information from the second network node identifying an IP address of the application server and the selected network access identifier; selecting, by the first network node, a third network node for operating as a user plane function (UPF) with respect to the current location of the wireless device and the selected network access identifier; and sending, to the third network node, the IP address of the application server for establishing a communication session between the wireless device and the application server via the third network node.

8. The method of clause 1, further comprising: receiving, at the first network node, the domain names and the list of network access identifiers from an application function (AF) ; and sending, by the first network node, the domain names and the list of network access identifiers prior to use as the second mapping prior to establishing a communication session with the wireless device.

9. The method of clause 1, further comprising: receiving, at the first network node, a plurality of domain names and a plurality of lists of network access identifiers from multiple application functions (AFs) ; and sending, by the first network node, the plurality of domain names and the plurality of lists of network access identifiers prior to use as second mappings prior to establishing a communication session with the wireless device.

10. The method of any one or more of clauses 1–9, wherein the second network node configured as the DNS resolver is a PDU session anchor user plane function (UPF) .

11. The method of any one or more of clauses 1–9, wherein the second network node configured as the DNS resolver is a standalone 5G core network function.

12. The method of any one or more of clauses 1–11, wherein the first network node is configured to notify the wireless device regarding availability of a new IP prefix using an IP v6 router advertisement message.

13. The method of any one or more of clauses 2–12, wherein the IP address of the at least one local DNS server and the match identifying the selected network access identifier are both determined at the second network node to reduce computational processing burden on the first network node.

14. The method of any one or more of clauses 1–12, wherein the first network node is a session management function (SMF) of a 5G wireless network, the one or more second network nodes are localized DNS Resolvers (LDNSRs) communicably coupled to the SMF, the list of network access identifiers corresponds to a Data Network Access Identifier (DNAI) list, and a domain name corresponds to a fully qualified domain name (FQDN) .

15. A method (e.g., method 800 depicted in FIG. 8) for wireless communications comprising: receiving (802) , at a domain name service (DNS) resolver node, a mapping between domain names and a set of network access identifiers for accessing data networks; upon receiving a DNS query comprising a requested domain name originating from a wireless device, the DNS resolver node determining (804) a network access identifier based on the mapping information and the requested domain name; and in response to receiving from a DNS server an IP address of an application server configured to serve a current location of the wireless device, sending (806) , by the DNS resolver node, the IP address of the application server to the wireless device.

16. The method of clause 15, wherein the set of network access identifiers is a second set of network identifiers, and the mapping between the domain names and the second set of network access identifiers is a second mapping, wherein prior to receiving the second mapping the DNS resolver node is configured to receive a first mapping, further comprising: receiving, at the DNS resolver node, from a core network node the first mapping between a first set of network access identifiers for accessing the data networks and IP addresses of local domain name service (L-DNS) servers that are configured to process DNS queries from wireless devices for identifying an application server in a plurality of application servers.

17. The method of clause 15, wherein the set of network access identifiers is a second set of network identifiers, and the mapping between the domain names and the second set of network access identifiers is a second mapping, wherein prior to receiving the second mapping the DNS resolver node is configured to receive a first mapping, further comprising: receiving, at the DNS resolver node, from a core network node the first mapping between a first set of network access identifiers for accessing the data networks and a dedicated IP address corresponding to an edns-client-subnet (ECS) option.

18. The method of clause 16, further comprising: determining, at the DNS resolver node, the IP address of the L-DNS server based on the first mapping information and a selected network access identifier corresponding to a match between a requested domain name included in the DNS query and the domain names included in the second mapping; and forwarding, at the DNS resolver node, the DNS queries message towards the L-DNS server determined based on the first mapping information and the selected network access identifier corresponding to the match.

19. The method of clause 17, further comprising: determining, at the DNS resolver node, the dedicated IP address based on the first mapping information and a selected network access identifier corresponding to a match between a requested domain name included in the DNS query and the domain names included in the second mapping; adding, by the DNS resolver node, the dedicated IP address of a centralized DNS (C-DNS) server as the ECS option to the DNS query; and forwarding, by the DNS resolver node, the DNS query towards the C-DNS server.

20. The method of clause 15, further comprising: sending, to the core network node, a notification message that includes the IP address of the application server and a selected network access identifier corresponding to a match between a requested domain name included in the DNS query and the domain names included in the mapping.

21. The method of clause 15, wherein the DNS query originating from the wireless device is initially received at a protocol data unit (PDU) session anchor and forwarded to the DNS resolver node.

22. The method of any one or more of clauses 16–21, wherein the first mapping is received from the core network node prior to the core network node establishing a session with the wireless device, and the second mapping is received from the core network node during establishment of a session with the wireless device.

23. The method of any one or more of clauses 16–21, wherein the first mapping is received from the core network node prior to the core network node establishing a session with the wireless device, and the second mapping is received from the core network node as a result of mobility of the wireless device.

24. The method of any one or more of clauses 16–23, wherein the DNS servers configured to process DNS queries from wireless devices are distinct from the DNS resolver node.

25. The method of any one or more of clauses 15–23, wherein the core network node is a session management function (SMF) of a 5G wireless network, the DNS resolver node is a localized DNS Resolver (LDNSR) communicably coupled to the SMF, the network access identifiers correspond to one or more lists of Data Network Access Identifiers (DNAIs) , and domain names correspond to one or more fully qualified domain names (FQDNs) .

26. The method of any one or more of clauses 16–25, wherein the second set of network access identifiers is based, at least in part, on a current location of the wireless device.

27. The method of any one or more of clauses 16–26, wherein the first set of network access identifiers and the second set of network access identifiers have at least one network access identifier in common.

28. The method of any one or more of clauses 1–27, wherein the application server corresponds to an edge application server and the plurality of application servers corresponds to a plurality of edge application servers.

29. An apparatus for wireless communication comprising a processor that is configured to carry out the method of any one or more of clauses 1–28.

30. A non-transitory computer readable medium having code stored thereon, the code when executed by a processor, causing the processor to implement a method recited in any one or more of clauses 1–28.

The disclosed and other embodiments, modules and the functional operations described in this document can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this document and their structural equivalents, or in combinations of one or more of them. The disclosed and other embodiments can be implemented as one or more computer program products, i.e., one or more modules of computer program instructions encoded on a computer readable medium for execution by, or to control the operation of, data processing apparatus. The computer readable medium can be a machine-readable storage device, a machine-readable storage substrate, a memory device, a composition of matter effecting a machine-readable propagated signal, or a combination of one or more them. The term “data processing apparatus” encompasses all apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, or multiple processors or computers. The apparatus can include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them. A propagated signal is an artificially generated signal, e.g., a machine-generated electrical, optical, or electromagnetic signal, that is generated to encode information for transmission to suitable receiver apparatus.

A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document) , in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or portions of code) . A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network.

The processes and logic flows described in this document can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit) .

Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read only memory or a random-access memory or both. The essential elements of a computer are a processor for performing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto optical disks, or optical disks. However, a computer need not have such devices. Computer readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto optical disks; and CD ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

While this patent document contains many specifics, these should not be construed as limitations on the scope of any invention or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular inventions. Certain features that are described in this patent document in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub combination or variation of a sub combination.

Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Moreover, the separation of various system components in the embodiments described in this patent document should not be understood as requiring such separation in all embodiments.

Only a few implementations and examples are described, and other implementations, enhancements, and variations can be made based on what is described and illustrated in this patent document.

From the foregoing, it will be appreciated that specific embodiments of the presently disclosed technology have been described herein for purposes of illustration, but that various modifications may be made without deviating from the scope of the invention. Accordingly, the presently disclosed technology is not limited except as by the appended claims.

Claims

A method for wireless communications comprising:

in response to a first network node receiving a session establishment request from a wireless device, providing to the wireless device, by the first network node, an IP address of a second network node included in one or more second network nodes, wherein the second network node is configured as a DNS resolver for serving one or more DNS queries from the wireless device; and

sending, by the first network node to the second network node, a mapping between domain names and a subset of network access identifiers included in a list of network access identifiers for accessing data networks, wherein the subset of network access identifiers is selected according to a current location of the wireless device.
The method of claim 1, wherein the mapping between the domain names and the subset of network access identifiers is a second mapping, wherein the first wireless network node is configured to send a first mapping prior to establishing a session with the wireless device, further comprising:

sending, by the first network node to the one or more second network nodes, the first mapping between at least one network access identifier for accessing the data networks and an IP address of at least one local domain name service (L-DNS) server that is configured to process DNS queries from wireless devices for identifying an application server in a plurality of application servers.
The method of claim 1, wherein the mapping between the domain names and the subset of network access identifiers is a second mapping, wherein the first wireless network node is configured to send a first mapping prior to establishing a session with the wireless device, further comprising:

sending, by the first network node to one or more second network nodes, a first mapping between at least one network access identifier for accessing the data networks and a dedicated IP address corresponding to an edns-client-subnet (ECS) option.
The method of claim 1, wherein the subset of network access identifiers at a first location of the wireless device is a first subset, further comprising:

upon determining the wireless device moved to a different second location from a first location, selecting, at the first network node, a second subset of network access identifiers from the list of network access identifiers based on the second location of the wireless device;

generating an updated second mapping using the second subset and associated domain names; and

sending the updated second mapping to the second network node.
The method of claim 1, further comprising:

receiving, from the second network node, a notification relating to a DNS response associated with a DNS query, wherein the notification relating to the DNS response includes an IP address of an application server serving a current location of the wireless device.
The method of claim 5, wherein the notification relating to the DNS response additionally includes a selected network access identifier corresponding to a match between a requested domain name included in the DNS query and the domain names included in the second mapping.
The method of claim 6, wherein the communication session is a protocol data unit (PDU) session, further comprising:

receiving, at the first network node, information from the second network node identifying an IP address of the application server and the selected network access identifier;

selecting, by the first network node, a third network node for operating as a user plane function (UPF) with respect to the current location of the wireless device and the selected network access identifier; and

sending, to the third network node, the IP address of the application server for establishing a communication session between the wireless device and the application server via the third network node.
The method of claim 1, further comprising:

receiving, at the first network node, the domain names and the list of network access identifiers from an application function (AF) ; and

sending, by the first network node, the domain names and the list of network access identifiers prior to use as the second mapping prior to establishing a communication session with the wireless device.
The method of claim 1, further comprising:

receiving, at the first network node, a plurality of domain names and a plurality of lists of network access identifiers from multiple application functions (AFs) ; and

sending, by the first network node, the plurality of domain names and the plurality of lists of network access identifiers prior to use as second mappings prior to establishing a communication session with the wireless device.
The method of any one or more of claims 1–9, wherein the second network node configured as the DNS resolver is a PDU session anchor user plane function (UPF) .
The method of any one or more of claims 1–9, wherein the second network node configured as the DNS resolver is a standalone 5G core network function.
The method of any one or more of claims 1–11, wherein the first network node is configured to notify the wireless device regarding availability of a new IP prefix using an IP v6 router advertisement message.
The method of any one or more of claims 2–12, wherein the IP address of the at least one local DNS server and the match identifying the selected network access identifier are both determined at the second network node to reduce computational processing burden on the first network node.
The method of any one or more of claims 1–12, wherein the first network node is a session management function (SMF) of a 5G wireless network, the one or more second network nodes are localized DNS Resolvers (LDNSRs) communicably coupled to the SMF, the list of network access identifiers corresponds to a Data Network Access Identifier (DNAI) list, and a domain name corresponds to a fully qualified domain name (FQDN) .
A method for wireless communications comprising:

receiving, at a domain name service (DNS) resolver node, a mapping between domain names and a set of network access identifiers for accessing data networks;

upon receiving a DNS query comprising a requested domain name originating from a wireless device, the DNS resolver node determining a network access identifier based on the mapping information and the requested domain name; and

in response to receiving from a DNS server an IP address of an application server configured to serve a current location of the wireless device, sending, by the DNS resolver node, the IP address of the application server to the wireless device.
The method of claim 15, wherein the set of network access identifiers is a second set of network identifiers, and the mapping between the domain names and the second set of network access identifiers is a second mapping, wherein prior to receiving the second mapping the DNS resolver node is configured to receive a first mapping, further comprising:

receiving, at the DNS resolver node, from a core network node the first mapping between a first set of network access identifiers for accessing the data networks and IP addresses of local domain name service (L-DNS) servers that are configured to process DNS queries from wireless devices for identifying an application server in a plurality of application servers.
The method of claim 15, wherein the set of network access identifiers is a second set of network identifiers, and the mapping between the domain names and the second set of network access identifiers is a second mapping, wherein prior to receiving the second mapping the DNS resolver node is configured to receive a first mapping, further comprising:

receiving, at the DNS resolver node, from a core network node the first mapping between a first set of network access identifiers for accessing the data networks and a dedicated IP address corresponding to an edns-client-subnet (ECS) option.
The method of claim 16, further comprising:

determining, at the DNS resolver node, the IP address of the L-DNS server based on the first mapping information and a selected network access identifier corresponding to a match between a requested domain name included in the DNS query and the domain names included in the second mapping; and

forwarding, at the DNS resolver node, the DNS queries message towards the L-DNS server determined based on the first mapping information and the selected network access identifier corresponding to the match.
The method of claim 17, further comprising:

determining, at the DNS resolver node, the dedicated IP address based on the first mapping information and a selected network access identifier corresponding to a match between a requested domain name included in the DNS query and the domain names included in the second mapping;

adding, by the DNS resolver node, the dedicated IP address of a centralized DNS (C-DNS) server as the ECS option to the DNS query; and

forwarding, by the DNS resolver node, the DNS query towards the C-DNS server.
The method of claim 15, further comprising:

sending, to the core network node, a notification message that includes the IP address of the application server and a selected network access identifier corresponding to a match between a requested domain name included in the DNS query and the domain names included in the mapping.
The method of claim 15, wherein the DNS query originating from the wireless device is initially received at a protocol data unit (PDU) session anchor and forwarded to the DNS resolver node.
The method of any one or more of claims 16–21, wherein the first mapping is received from the core network node prior to the core network node establishing a session with the wireless device, and the second mapping is received from the core network node during establishment of a session with the wireless device.
The method of any one or more of claims 16–21, wherein the first mapping is received from the core network node prior to the core network node establishing a session with the wireless device, and the second mapping is received from the core network node as a result of mobility of the wireless device.
The method of any one or more of claims 16–23, wherein the DNS servers configured to process DNS queries from wireless devices are distinct from the DNS resolver node.
The method of any one or more of claims 15–23, wherein the core network node is a session management function (SMF) of a 5G wireless network, the DNS resolver node is a localized DNS Resolver (LDNSR) communicably coupled to the SMF, the network access identifiers correspond to one or more lists of Data Network Access Identifiers (DNAIs) , and domain names correspond to one or more fully qualified domain names (FQDNs) .
The method of any one or more of claims 16–25, wherein the second set of network access identifiers is based, at least in part, on a current location of the wireless device.
The method of any one or more of claims 16–26, wherein the first set of network access identifiers and the second set of network access identifiers have at least one network access identifier in common.
The method of any one or more of claims 1–27, wherein the application server corresponds to an edge application server and the plurality of application servers corresponds to a plurality of edge application servers.
An apparatus for wireless communication comprising a processor that is configured to carry out the method of any one or more of claims 1–28.
A non-transitory computer readable medium having code stored thereon, the code when executed by a processor, causing the processor to implement a method recited in any one or more of claims 1–28.