In March, 2026, the CNIPA released the Guidelines for Invention Patent Applications Involving Standards. The Guidelines put forward specific suggestions for the drafting of application documents and response strategies for office actions, taking into account the considerations in inventiveness evaluation for patents involving standards. By referencing a practical case, this article analyzes the application of the Guidelines in practical drafting, hoping to invite insights and opinions and provide some enlightenment for subsequent drafting practice.

The Guidelines point out that the following two types of applications covering incremental refinements in communication technologies are more likely to be subject to inventiveness objections: (1) adjustment and refinement of technical means within the same generation or scenario; (2) technical improvement or integration across different generations or scenarios. The Guidelines recommend highlighting different contents in the application documents for these two types of applications.

Specifically speaking, for applications of type (1), it is recommended that the specification elaborate on practical bottlenecks in implementing the referenced standard and highlight differences and retained elements of the incremental adjustments and optimizations that embody the claimed invention’s contribution against earlier-generation or preceding standard releases; and the claims should clearly mark the features representing the improvement, limit the volume of prior art to prevent downplaying the essential features, and fully disclose all associated interconnected technical features.

Applications of type (2) fall into two categories: solutions applying conventional technical concepts to resolve technical problems peculiar to new-generation standards; and solutions formed by combining conventional technical concepts with specific technical elements of new-generation standards to address common technical problems carried over into new generations.

For applications for solutions addressing technical problems peculiar to new-generation standards, it is recommended that the specification set forth the applicable generation and the root causes of new problems, and elaborate on how the technical means integrate with new network architecture or functional elements; the claims should embody the features of the new generation, avoid overgeneralized description encompassing prior art of earlier generations, reflect substantial improvements and adjustments made to the technical means of previous generations as well as the in-depth technical integration between conventional approaches and the solution to new problems, so as not to be deemed as a straightforward adaptation of old technical ideas.

For applications for solutions to common technical problems carried over into new generations, the specification should reflect the in-depth integration of the technical means with the new system architecture or functional elements under the new-generation scenario, and clarify the differences in technical means from the means adopted in earlier generations as well as the corresponding technical effects. The claims may, in addition to emphasizing the dependence on the technical scenario of the new generation, disclose how the information indication method is adapted for the functional elements of the new generation, demonstrating that the prior art is not directly applicable due to the constraints in the scenario before technological upgrade.

For example, in drafting the application document for a technical solution relating to a dual-SIM UE, it is necessary to first objectively determine whether the solution spans different generations, and whether it addresses a technical problem unique to the new generation, or a technical problem that is carried over across generations. In the 4G era, dual-SIM standby schemes for dual-SIM UEs were already prevalent, enabling two SIM cards being simultaneously registered with the 4G network and remaining in standby mode. If the technical solution concerns improvements to the dual-SIM functionality of the UE, the problem to be solved is likely one evolved and carried over across 4G to 5G.

For a technical solution addressing technical problems that is carried over across generations, the Guidelines recommend drafting the specification to indicate the differences in technical means from the means adopted in earlier generations and drafting the claims to reflect the features of the new generation as well as the adjustments to relevant technical means to adapt to the new-generation scenario. If the specification focuses on the 5G standard and fails to specify the improvements made on the basis of 4G, the claimed technical solution may be, during prosecution, regarded as a mere substitution of technical means from 4G to 5G and thus subject to repetitive inventiveness objections in view of 4G-related prior art, and may ultimately receive a decision of rejection. A practical example is introduced subsequently for further illustration.

i. Specification: elaborating differences in technical means from the means adopted in earlier generations

In the 4G network, a dual-SIM UE basically receives paging passively. If the UE fails to respond to paging because another USIM card is engaged in a higher-priority service, repeated paging attempts or anomalies on the network side would occur. The 4G core network (e.g., the Mobility Management Entity, MME) performs paging and NAS state management in accordance with procedures defined in the 4G standards. However, the 4G standards do not define specific UE-initiated messages and corresponding procedures for negotiating dual-SIM coordination with the MME. Although device vendors implemented dual-SIM standby in the 4G era based on optimizations to the UE protocol stack software and other modules, each SIM card is considered, at the 4G standard level, as a standalone UE and there is no such a mechanism under which a single MME is enabled to associate with and manage two SIM cards simultaneously. For instance, the Non‑Access Stratum (NAS) message specified in the 4G standards does not contain an information element for indicating relevant information of the second SIM card.

Paging issues associated with the dual-SIM solution may involve the information element (IE) of Paging Cause. In the existing paging mechanism, though the paging request delivered by the core network to the base station carries a CN Domain indicator (for identifying CS voice or PS data), the 4G standards do not allow the core network to transparently transmit specific paging causes or fine-grained priority levels to the UE. In the 4G system, after the UE receives the paging and establishes a NAS signaling connection (i.e., establishing a signaling channel for subsequent services by operations of the network control layer), the user may decide to reject the incoming call (i.e., a user service layer operation).

In the drafting of a patent application relating to dual-SIM technologies, it would be advisable to elaborate on at least part of the afore-mentioned differences of the claimed invention from the solutions addressing general technical problems and those arising in earlier generations. This facilitates a proper understanding of the background and the inventiveness level of the claimed technical solution.

ii. Claims: reflecting features of the new generation and the adjustments to relevant technical means to adapt to the new-generation scenario

Based on the foregoing differences elaborated in the specification, the claims directed to the dual-SIM UE may, for example, recite limitations covering the following aspects: receiving, from the mobility management node, a paging cause for the second SIM card; and transmitting, to the mobility management node, a rejection message indicating that the UE declines to respond to the paging for the second SIM card.

As mentioned previously, the 4G standards only define a mechanism in which the mobility management node (e.g., the MME) communicates with base stations on the paging cause, and does not define any mechanism for communicating the paging cause with the UE. Furthermore, the UE cannot reject a paging in the 4G framework, much less signaling a rejection to the network side.

Further, the following features may be recited at least in part to highlight the distinctions over the prior art: establishing, by the UE, a NAS signaling connection for the first SIM card; during the NAS signaling connection of the first SIM card, receiving, from the mobility management node, a NAS message containing the paging cause for the second SIM card; and transmitting, to the mobility management node and by the UE, a message of an attempt to release the NAS signaling connection for the first SIM card. As discussed above, the 4G framework does not allow the UE to perform signaling interaction related to the secondary SIM card before the service of the primary SIM card is completely terminated.

In the event that the subject technical problem concerns, e.g., the dual-SIM technology also exist in the previous generation (4G) wireless communication technology, the application document may be drafted to make clear the differences in technical means from the means adopted in earlier generations in the specification and set forth features of the new generation and the adjustments to relevant technical means to adapt to the new-generation scenario in the claims, as recommended by the Guidelines for the drafting of patent applications involving problems carried over across 4G and 5G. This could help applicants to strive for a favorable examination result.